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Clinical Glossary with Etymology

Comprehensive glossary of medical, genetic, and neurological terms with etymological information

Verified Owner: Lucas Steuber

Glossary of Terms with Etymology

Owner: Lucas Steuber Verification: Verified Tags: clinical guidance, references

ABA (Applied Behavior Analysis): A therapy based on the science of learning and behavior, commonly used to improve social, communication, and learning skills through reinforcement strategies. Etymology: "Applied" refers to the practical application of the principles of behavior analysis. "Behavior" refers to the actions or responses of an organism. "Analysis" refers to the systematic study and understanding of behavior. A-B-A-B Design: A research design used in ABA to demonstrate the effectiveness of an intervention by comparing behavior under baseline conditions (A), intervention conditions (B), a return to baseline (A), and a reintroduction of the intervention (B). Etymology: "A" represents baseline conditions. "B" represents intervention conditions. A-B-A Design: A research design used in ABA to demonstrate the effectiveness of an intervention by comparing behavior under baseline conditions (A) and intervention conditions (B), followed by a return to baseline (A). Etymology: "A" represents baseline conditions. "B" represents intervention conditions. Abative Effects: A decrease in the reinforcing value of a stimulus due to the presentation of another stimulus. Etymology: "Abative" refers to a reduction or decrease. "Effects" refers to the consequences of a stimulus. ABC Continuous Recording: A method of data collection in ABA that involves recording the antecedent (A), behavior (B), and consequence (C) of each instance of a target behavior. Etymology: "ABC" refers to the three components of the behavioral sequence: antecedent, behavior, and consequence. "Continuous" refers to the recording of every instance of the behavior. ABC Narrative Recording: A method of data collection in ABA that involves writing a detailed description of the antecedent, behavior, and consequence of a target behavior. Etymology: "ABC" refers to the three components of the behavioral sequence: antecedent, behavior, and consequence. "Narrative" refers to a story or description. ABC Recording: A method of data collection in ABA that involves recording the antecedent, behavior, and consequence of a target behavior. Etymology: "ABC" refers to the three components of the behavioral sequence: antecedent, behavior, and consequence. Agenesis: The absence of an organ due to its failure to develop during embryonic growth. Etymology: "A-" means "without" or "lack of." "Genesis" refers to the origin or creation. Agnosia: The inability to recognize objects, persons, sounds, shapes, or smells despite having no significant memory loss. Etymology: "A-" means "without" or "lack of." "Gnosis" refers to knowledge or perception. Agraphia: The loss of the ability to write, typically due to a brain injury or neurological disorder. Etymology: "A-" means "without" or "lack of." "Graphein" refers to writing. Aicardi Syndrome: A rare genetic disorder characterized by the absence of the corpus callosum, infantile spasms, and chorioretinal lacunae. Etymology: Named after the French neurologist Jean Aicardi who first described the syndrome in 1965. Akathisia: A movement disorder characterized by an inner feeling of restlessness and an inability to stay still. Etymology: "A-" means "without" or "lack of." "Kathexis" refers to a state of being bound or fixed. Alexia: The inability to read due to brain damage. Etymology: "A-" means "without" or "lack of." "Lexis" refers to words or language. Amniocentesis: A prenatal diagnostic procedure where a small amount of amniotic fluid is extracted for genetic testing or to detect fetal infections. Etymology: "Amnion" refers to the membrane that surrounds the fetus. "Centesis" refers to the surgical puncture of a body cavity. Amyotrophic Lateral Sclerosis (ALS): A progressive neurodegenerative disease affecting nerve cells in the brain and spinal cord, leading to muscle weakness and atrophy. Etymology: "A-" means "without" or "lack of." "Myo" refers to muscle. "Trophic" refers to nourishment. "Lateral" refers to the sides. "Sclerosis" refers to hardening. Angelman Syndrome: A genetic disorder causing developmental disabilities, seizures, speech impairment, and a characteristic happy demeanor. Etymology: Named after the British pediatrician Harry Angelman who first described the syndrome in 1965. Angioedema: Swelling of the deeper layers of the skin, often around the eyes and lips, usually due to an allergic reaction. Etymology: "Angio" refers to blood vessels. "Edema" refers to swelling. Aniridia: A rare genetic disorder characterized by the complete or partial absence of the iris, the colored part of the eye. Etymology: "A-" means "without" or "lack of." "Iris" refers to the colored part of the eye. Anosmia: The loss or impairment of the sense of smell. Etymology: "A-" means "without" or "lack of." "Osme" refers to smell. Anoxia: An absence of oxygen supply to an organ or a tissue. Etymology: "A-" means "without" or "lack of." "Oxys" refers to oxygen. Aphasia: A condition characterized by the loss of the ability to understand or express speech, caused by brain damage. Etymology: "A-" means "without" or "lack of." "Phasis" refers to speech. Apraxia: A motor disorder caused by damage to the brain, resulting in difficulty with the motor planning to perform tasks or movements when asked. Etymology: "A-" means "without" or "lack of." "Praxis" refers to action or doing. Arbitrarily Applicable Relational Responding (AARR): A concept in ABA that refers to the ability to learn new relations based on previously learned relations, even if the new relations are not directly taught. Etymology: "Arbitrary" refers to something that is not determined by reason or logic. "Applicable" refers to something that can be used or applied. "Relational" refers to a relationship between two or more things. "Responding" refers to a behavior or action. Assistive Technology (AT): Devices or systems that help maintain or improve an individual's ability to perform tasks that they would otherwise be unable to accomplish. Etymology: "Assist" refers to helping or aiding. "Technology" refers to the application of scientific knowledge for practical purposes. Ataxia: A lack of muscle coordination affecting speech, eye movements, the ability to swallow, walking, and other voluntary movements. Etymology: "A-" means "without" or "lack of." "Taxis" refers to order or coordination. Atopic Dermatitis: A chronic skin condition characterized by inflamed, itchy skin, also known as eczema. Etymology: "Atopic" refers to a predisposition to allergies. "Dermatitis" refers to inflammation of the skin.

B

Baseline: The initial phase of a research design in ABA, where behavior is measured before the introduction of an intervention. Etymology: "Base" refers to the starting point. "Line" refers to a level or measurement. Behavior Modification: Techniques used to increase or decrease a particular behavior through reinforcement, punishment, or other behavioral strategies. Etymology: "Behavior" refers to the actions or responses of an organism. "Modification" refers to the process of changing or altering. Behavioral Analysis: The scientific study of behavior, including its causes and consequences. Etymology: "Behavior" refers to the actions or responses of an organism. "Analysis" refers to the systematic study and understanding of behavior. Behavioral Intervention: A plan or strategy designed to change a specific behavior. Etymology: "Behavior" refers to the actions or responses of an organism. "Intervention" refers to an action taken to influence or change something. Behavioral Momentum: The tendency for a behavior to continue occurring after it has been reinforced. Etymology: "Behavior" refers to the actions or responses of an organism. "Momentum" refers to the force or energy that keeps something moving. Behavioral Objective: A specific, measurable, achievable, relevant, and time-bound (SMART) goal for a behavior change. Etymology: "Behavior" refers to the actions or responses of an organism. "Objective" refers to a goal or aim. Behavioral Repertoire: The set of behaviors that an individual is capable of performing. Etymology: "Behavior" refers to the actions or responses of an organism. "Repertoire" refers to a collection or range of things. Bipolar Disorder: A mental disorder marked by alternating periods of elation (mania) and depression. Etymology: "Bi" means "two." "Polar" refers to the opposite ends of a spectrum. Bradykinesia: Extreme slowness of movements and reflexes, often a symptom of neurological disorders like Parkinson's disease. Etymology: "Brady" means "slow." "Kinesis" refers to movement. Brachycephaly: A condition characterized by a broad, short skull, usually the result of premature closure of the coronal sutures. Etymology: "Brachy" means "short." "Cephal" refers to the head. Bronchopulmonary Dysplasia: A serious lung condition that affects infants, especially those who are born prematurely or who have received prolonged mechanical ventilation. Etymology: "Broncho" refers to the bronchi (airways in the lungs). "Pulmonary" refers to the lungs. "Dysplasia" refers to abnormal development.

C

CAG Repeat: A segment of DNA in which a sequence of three nucleotides (cytosine, adenine, and guanine) is repeated multiple times. Expansion of CAG repeats is associated with certain genetic disorders, such as Huntington's disease. Etymology: "CAG" refers to the three nucleotides cytosine, adenine, and guanine. "Repeat" refers to the repetition of a sequence. Cardiomegaly: An enlarged heart, often indicative of underlying heart disease. Etymology: "Cardio" refers to the heart. "Megaly" refers to enlargement. Cataplexy: A sudden loss of muscle tone triggered by strong emotions, often associated with narcolepsy. Etymology: "Cata" means "down" or "against." "Plexis" refers to a network or interlacing. Cerebral Palsy (CP): A group of disorders affecting movement, muscle tone, and posture, caused by damage to the developing brain, most often before birth. Etymology: "Cerebral" refers to the brain. "Palsy" refers to paralysis or weakness. Chaining: A procedure in ABA that involves teaching a complex behavior by breaking it down into smaller steps and then linking those steps together. Etymology: "Chain" refers to a series of connected links. Chorionic Villus Sampling (CVS): A prenatal test in which a sample of chorionic villi is removed from the placenta for genetic testing. Etymology: "Chorionic" refers to the chorion, the outermost membrane surrounding the fetus. "Villus" refers to a small, finger-like projection. "Sampling" refers to the process of taking a small sample. Chromosomal Microarray Analysis (CMA): A high-resolution method for detecting chromosomal abnormalities that can identify submicroscopic deletions and duplications. Etymology: "Chromosome" refers to a thread-like structure that carries genetic information. "Microarray" refers to a technology that allows for the analysis of thousands of DNA sequences simultaneously. "Analysis" refers to the process of examining and interpreting data. Clinodactyly: A congenital condition where a finger is curved or bent, typically the fifth finger (pinky). Etymology: "Clino" means "to bend." "Dactyl" refers to a finger or toe. Cognitive Behavioral Therapy (CBT): A type of therapy that focuses on changing negative thoughts and behaviors. Etymology: "Cognitive" refers to mental processes. "Behavioral" refers to actions or responses. "Therapy" refers to the treatment of disease or injury. Cognitive Rehabilitation: A therapeutic approach designed to improve cognitive functions such as memory, attention, and problem-solving skills. Etymology: "Cognitive" refers to mental processes. "Rehabilitation" refers to the process of restoring function. Conditioned Reinforcer: A stimulus that has acquired reinforcing properties through association with a primary reinforcer. Etymology: "Conditioned" refers to something that has been learned. "Reinforcer" refers to a stimulus that increases the likelihood of a behavior. Congenital Anomalies: Structural or functional anomalies that occur during intrauterine life and can be identified prenatally, at birth, or later in life. Etymology: "Congenital" refers to a condition present at birth. "Anomaly" refers to a deviation from the normal. Consequence: The event that follows a behavior and influences the likelihood of that behavior occurring again. Etymology: "Con" means "with" or "together." "Sequence" refers to a series of events. Coarctation of the Aorta: A congenital heart defect characterized by a narrowing of the aorta. Etymology: "Coarctation" refers to narrowing or constriction. "Aorta" refers to the main artery that carries blood from the heart to the body. Corticobasal Degeneration: A progressive neurological disorder characterized by nerve cell loss and atrophy of multiple areas of the brain. Etymology: "Cortico" refers to the cerebral cortex. "Basal" refers to the base of the brain. "Degeneration" refers to the deterioration or breakdown of cells or tissues. Cumulative Record: A graph used in ABA to display the total number of responses over time. Etymology: "Cumulative" refers to the total amount. "Record" refers to a written or recorded account. Cystic Fibrosis: A genetic disorder that affects the respiratory and digestive systems, causing severe lung damage and nutritional deficiencies. Etymology: "Cystic" refers to a sac-like structure. "Fibrosis" refers to the formation of scar tissue. Contact Dermatitis: Skin inflammation caused by direct contact with an irritant or allergen. Etymology: "Contact" refers to direct touch. "Dermatitis" refers to inflammation of the skin.

D

Dandy-Walker Syndrome: A congenital brain malformation involving the cerebellum and the fluid-filled spaces around it, leading to developmental delays and motor challenges. Etymology: Named after the American neurosurgeons Walter Dandy and Arthur Earl Walker who first described the syndrome in 1942. Data Collection: The process of gathering information about a behavior. Etymology: "Data" refers to information. "Collection" refers to the process of gathering or assembling. Data Analysis: The process of examining and interpreting data to draw conclusions. Etymology: "Data" refers to information. "Analysis" refers to the systematic study and understanding of behavior. Dementia: A group of symptoms affecting memory, thinking, and social abilities severely enough to interfere with daily functioning. Etymology: "De-" means "away from" or "lack of." "Mens" refers to mind. Dependent Variable: The behavior that is being measured in a research design. Etymology: "Dependent" refers to something that is influenced by something else. "Variable" refers to a factor that can change. Developmental Delay: A condition where a child is behind in reaching developmental milestones compared to peers, which can affect cognitive, physical, social, and emotional development. Etymology: "Development" refers to the process of growth and change. "Delay" refers to a slowing down or postponement. Differential Reinforcement: A procedure in ABA that involves reinforcing a desired behavior while withholding reinforcement for an undesired behavior. Etymology: "Differential" refers to the difference between two things. "Reinforcement" refers to a stimulus that increases the likelihood of a behavior. Discriminative Stimulus (SD): A stimulus that signals that a particular behavior will be reinforced. Etymology: "Discriminative" refers to the ability to distinguish between two things. "Stimulus" refers to an event or object that elicits a response. "SD" is an abbreviation for "Discriminative Stimulus." Down Syndrome (Trisomy 21): A genetic disorder caused by the presence of an extra copy of chromosome 21, leading to intellectual disability, characteristic facial features, and various health issues. Etymology: Named after the British physician John Langdon Down who first described the syndrome in 1866. "Trisomy" refers to the presence of three copies of a chromosome.

E

Echocardiography: An ultrasound-based diagnostic tool used to visualize the heart and assess its function and structure. Etymology: "Echo" refers to the reflection of sound waves. "Cardio" refers to the heart. "Graphy" refers to the process of recording or writing. Echolalia: The repetition of words or phrases spoken by another person. Etymology: "Echo" refers to the repetition of sound. "Lalia" refers to speech. Electromyography (EMG): A diagnostic procedure that assesses the health of muscles and the nerve cells that control them by measuring electrical activity. Etymology: "Electro" refers to electricity. "Myo" refers to muscle. "Graphy" refers to the process of recording or writing. Elopement: A behavior in ABA that refers to a child running away from a safe or supervised area. Etymology: "Elope" refers to running away secretly. "Ment" refers to the act of doing something. Epicanthal Folds: Skin folds of the upper eyelid covering the inner corner of the eye, commonly found in certain genetic conditions. Etymology: "Epi" means "upon" or "over." "Canthus" refers to the corner of the eye. "Fold" refers to a crease or bend. Epilepsy: A neurological disorder marked by recurrent, unprovoked seizures due to abnormal electrical activity in the brain. Etymology: "Epi" means "upon" or "over." "Leptein" refers to to seize or grasp. Esotropia: A form of strabismus in which one or both eyes turn inward. Etymology: "Eso" means "inward." "Tropia" refers to a turning or deviation. Ethical Considerations: The principles and guidelines that govern the conduct of ABA practitioners. Etymology: "Ethical" refers to moral principles. "Considerations" refers to things that need to be thought about. Executive Function: Higher-order cognitive processes that include planning, decision-making, error correction, and troubleshooting. Etymology: "Executive" refers to a person or group that has the power to make decisions. "Function" refers to a specific activity or purpose.

F

Fading: A procedure in ABA that involves gradually reducing the intensity or frequency of a prompt or cue. Etymology: "Fade" refers to gradually disappearing. "ing" refers to the process of doing something. Fear of Dental Procedures: A common phobia that can be addressed using ABA techniques. Etymology: "Fear" refers to an unpleasant emotion caused by danger or threat. "Dental" refers to teeth. "Procedures" refers to a series of actions or steps. Feeding Disorders: Difficulties with eating that can be caused by a variety of factors, including medical conditions, developmental delays, and behavioral issues. Etymology: "Feeding" refers to the act of providing food. "Disorder" refers to a disturbance or malfunction. Figure Skating: A sport that can be analyzed and improved using ABA principles. Etymology: "Figure" refers to a pattern or design. "Skating" refers to the act of moving on ice skates. Fire Safety: A critical skill that can be taught using ABA techniques. Etymology: "Fire" refers to a burning flame. "Safety" refers to the state of being free from harm. Fixed-Interval (FI) Schedule: A reinforcement schedule in which reinforcement is delivered for the first response after a fixed amount of time has elapsed. Etymology: "Fixed" refers to something that is set or unchanging. "Interval" refers to a period of time. "FI" is an abbreviation for "Fixed-Interval." Fixed-Ratio (FR) Schedule: A reinforcement schedule in which reinforcement is delivered after a fixed number of responses. Etymology: "Fixed" refers to something that is set or unchanging. "Ratio" refers to a relationship between two quantities. "FR" is an abbreviation for "Fixed-Ratio." Fragile X Syndrome: A genetic disorder characterized by intellectual disability, behavioral and learning challenges, and various physical features. Etymology: Named for the fragile appearance of the X chromosome in individuals with the disorder. Frontal Lobe Epilepsy: A form of epilepsy characterized by seizures originating in the frontal lobes of the brain. Etymology: "Frontal" refers to the front of the brain. "Lobe" refers to a distinct part of the brain. "Epilepsy" refers to a neurological disorder marked by seizures. Fukuyama Congenital Muscular Dystrophy: A form of muscular dystrophy that affects the muscles and brain, leading to progressive muscle weakness and brain malformations. Etymology: Named after the Japanese physician Yoshiaki Fukuyama who first described the syndrome in 1960.

G

Gait Trainer: A device used to help individuals learn to walk or improve their walking ability, often used in physical therapy. Etymology: "Gait" refers to a manner of walking. "Trainer" refers to a device or person that helps with learning or improvement. Gambling: A behavior that can be analyzed and treated using ABA principles. Etymology: "Gamble" refers to the act of risking something on an uncertain outcome. Gamification: The process of incorporating game-like elements into non-game contexts to increase engagement and motivation. Etymology: "Game" refers to a form of entertainment. "fication" refers to the process of making something into something else. Gender-Based Violence: A form of violence that is directed at an individual based on their gender. Etymology: "Gender" refers to the social and cultural roles and behaviors associated with being male or female. "Based" refers to something that is founded or dependent on something else. "Violence" refers to physical force used to harm or injure. Generalization: The ability for a learned behavior to occur in different settings or with different stimuli. Etymology: "General" refers to something that is widespread or common. "ization" refers to the process of making something general. Genotype-Phenotype Correlation: The relationship between the genetic makeup (genotype) of an individual and the observable physical and behavioral characteristics (phenotype). Etymology: "Genotype" refers to the genetic makeup of an individual. "Phenotype" refers to the observable characteristics of an individual. "Correlation" refers to a relationship between two variables. Gerontology: The study of aging. Etymology: "Geron" is a Greek word meaning "old man." "logy" refers to the study of something. Goal Setting: The process of establishing specific, measurable, achievable, relevant, and time-bound (SMART) goals for behavior change. Etymology: "Goal" refers to an aim or objective. "Setting" refers to the process of establishing or determining. Golf: A sport that can be analyzed and improved using ABA principles. Etymology: "Golf" is a game played with a club and ball on a course with 18 holes. Gonadotropin-Releasing Hormone (GnRH): A hormone responsible for the release of follicle-stimulating hormone and luteinizing hormone from the anterior pituitary. Etymology: "Gonadotropin" refers to a hormone that stimulates the gonads (testes or ovaries). "Releasing" refers to the process of releasing a substance. "Hormone" refers to a chemical messenger. Growth Hormone Deficiency: A medical condition characterized by the inadequate secretion of growth hormone from the anterior pituitary gland, leading to stunted growth in children and various health issues in adults. Etymology: "Growth" refers to the process of increasing in size. "Hormone" refers to a chemical messenger. "Deficiency" refers to a lack of something essential. Gun Safety: A critical skill that can be taught using ABA techniques. Etymology: "Gun" refers to a firearm. "Safety" refers to the state of being free from harm.

H

Hairpulling: A behavior that can be analyzed and treated using ABA principles. Etymology: "Hair" refers to the strands that grow from the scalp. "Pulling" refers to the act of removing something by force. Hemiplegia: Paralysis of one side of the body, often resulting from a stroke or other brain injury. Etymology: "Hemi" means "half." "Plegia" refers to paralysis. Hemizygous: Having only one allele of a gene instead of the typical two, often used in reference to genes on the X chromosome in males. Etymology: "Hemi" means "half." "Zygo" refers to a pair or union. Heterozygous: Having two different alleles for a specific gene. Etymology: "Hetero" means "different." "Zygo" refers to a pair or union. Hirschsprung Disease: A congenital condition characterized by the absence of nerve cells in parts of the colon, causing severe constipation and intestinal obstruction. Etymology: Named after the German surgeon Harald Hirschsprung who first described the condition in 1886. Holoprosencephaly: A birth defect in which the forebrain fails to develop into two hemispheres, leading to severe neurological and facial abnormalities. Etymology: "Holo" means "whole" or "entire." "Pros" means "forward" or "in front of." "Encephal" refers to the brain. Huntington's Disease: A genetic disorder that causes progressive degeneration of nerve cells in the brain, leading to motor dysfunction, cognitive decline, and psychiatric symptoms. Etymology: Named after the American physician George Huntington who first described the disease in 1872.

I

ICD-11: The 11th revision of the International Classification of Diseases, a global standard for diagnostic health information. Etymology: "ICD" stands for "International Classification of Diseases." "11" refers to the 11th revision. Idiopathic: Pertaining to a condition with no identifiable cause. Etymology: "Idio" means "one's own" or "peculiar." "Path" refers to disease. Independent Variable: The intervention or treatment that is being manipulated in a research design. Etymology: "Independent" refers to something that is not influenced by something else. "Variable" refers to a factor that can change. Individualized Education Program (IEP): A plan developed for students with disabilities that outlines their educational needs and goals. Etymology: "Individualized" refers to something that is tailored to a specific person. "Education" refers to the process of learning. "Program" refers to a plan or course of action. Intellectual Disability: A condition characterized by significant limitations in both intellectual functioning and adaptive behavior, affecting conceptual, social, and practical skills. Etymology: "Intellectual" refers to the ability to think and reason. "Disability" refers to a condition that limits a person's ability to perform certain activities. Interobserver Agreement (IOA): A measure of the consistency between two or more observers' recordings of a behavior. Etymology: "Inter" means "between." "Observer" refers to a person who watches and records behavior. "Agreement" refers to consistency or similarity. Intracranial Hypertension: Elevated pressure within the skull, which can cause headaches, vision problems, and other neurological symptoms. Etymology: "Intra" means "within." "Cranial" refers to the skull. "Hypertension" refers to high blood pressure. Intraventricular Hemorrhage: Bleeding into the brain's ventricular system, a condition commonly seen in premature infants. Etymology: "Intra" means "within." "Ventricular" refers to the ventricles of the brain. "Hemorrhage" refers to bleeding. Intrauterine Growth Restriction (IUGR): A condition where a fetus is smaller than expected for the number of weeks of pregnancy, often due to placental problems. Etymology: "Intra" means "within." "Uterine" refers to the uterus. "Growth" refers to the process of increasing in size. "Restriction" refers to a limitation.

J

Joubert Syndrome: A rare genetic disorder characterized by a distinctive malformation of the cerebellum, leading to developmental delays, breathing problems, and other neurological issues. Etymology: Named after the American physician Michel Joubert who first described the syndrome in 1969. Juvenile Myoclonic Epilepsy: A type of epilepsy that begins in adolescence and is characterized by myoclonic jerks, generalized tonic-clonic seizures, and absence seizures. Etymology: "Juvenile" refers to youth. "Myoclonic" refers to sudden, brief muscle jerks. "Epilepsy" refers to a neurological disorder marked by seizures.

K

Karyotyping: A laboratory procedure that examines an individual's chromosomes to identify genetic abnormalities. Etymology: "Karyo" refers to the nucleus of a cell. "Typing" refers to the process of classifying or identifying. Klinefelter Syndrome: A genetic condition in males caused by an extra X chromosome (47,XXY), leading to physical and cognitive development issues. Etymology: Named after the American physician Harry Klinefelter who first described the syndrome in 1942.

L

Latency: The time that elapses between a stimulus and a response. Etymology: "Latent" refers to something that is hidden or inactive. "cy" refers to a state or condition. Least Restrictive Environment (LRE): A principle in education that requires students with disabilities to be educated in the setting that is most similar to that of their non-disabled peers. Etymology: "Least" refers to the smallest amount. "Restrictive" refers to something that limits or restricts. "Environment" refers to the surroundings or conditions. Level System: A behavior management system in ABA that uses a hierarchy of levels to track progress and provide reinforcement. Etymology: "Level" refers to a stage or rank. "System" refers to a set of interconnected parts. Lissencephaly: A rare brain disorder where the surface of the brain appears smooth due to defective neuronal migration during embryonic development. Etymology: "Liss" means "smooth." "Encephal" refers to the brain. Low-Set Ears: A physical characteristic where the ears are positioned lower on the head than usual, often associated with certain genetic conditions. Etymology: "Low" refers to a position below the normal level. "Set" refers to the position or placement. "Ears" refers to the organs of hearing. Luteinizing Hormone (LH): A hormone that triggers ovulation and the release of the egg from the ovary in females, and stimulates testosterone production in males. Etymology: "Luteinizing" refers to the formation of the corpus luteum, a temporary endocrine gland in the ovary. "Hormone" refers to a chemical messenger. Lymphedema: Swelling typically in the arms or legs due to a lymphatic system blockage, common in individuals with Turner Syndrome. Etymology: "Lymph" refers to the fluid that circulates in the lymphatic system. "Edema" refers to swelling.

M

Macrocephaly: An abnormally large head, which may be a sign of an underlying genetic or neurological condition. Etymology: "Macro" means "large." "Cephal" refers to the head. Macroglossia: An unusually large tongue, often associated with genetic conditions like Down Syndrome. Etymology: "Macro" means "large." "Glossia" refers to the tongue. Maintenance: The process of keeping a behavior at a desired level after it has been acquired. Etymology: "Maintain" refers to keeping something in a particular state. "ance" refers to the process of doing something. Mand: A verbal behavior that is used to request or demand something. Etymology: "Mand" is a term coined by B.F. Skinner to describe a type of verbal behavior. Marinesco-Sjogren Syndrome: A rare genetic disorder characterized by ataxia, dementia, and other neurological symptoms. Etymology: Named after the Romanian neurologist Grigore Marinesco and the Swedish ophthalmologist Olof Sjogren who first described the syndrome in 1931 and 1941, respectively. Megalencephaly: An abnormally large brain, which can be associated with various neurological disorders. Etymology: "Mega" means "large." "Encephal" refers to the brain. Microcephaly: A condition where the head is significantly smaller than expected, often due to abnormal brain development. Etymology: "Micro" means "small." "Cephal" refers to the head. Micrognathia: An abnormally small jaw, which can cause feeding and breathing difficulties and is associated with several genetic syndromes. Etymology: "Micro" means "small." "Gnathia" refers to the jaw. Miltenberger's Law: A principle in ABA that states that the more frequently a behavior is reinforced, the more likely it is to occur. Etymology: Named after the American psychologist Raymond G. Miltenberger. Motivating Operation (MO): A variable that alters the reinforcing value of a stimulus. Etymology: "Motivate" refers to the process of providing a reason for doing something. "Operation" refers to a process or action. "MO" is an abbreviation for "Motivating Operation." Multiple Baseline Design: A research design in ABA that involves introducing an intervention to different behaviors, settings, or individuals at different times. Etymology: "Multiple" refers to more than one. "Baseline" refers to the initial phase of a research design. "Design" refers to a plan or structure. Muscular Dystrophy: A group of genetic diseases characterized by progressive weakness and degeneration of the skeletal muscles. Etymology: "Muscular" refers to muscles. "Dystrophy" refers to abnormal development or nourishment. Myoclonic Seizures: Sudden, brief, involuntary muscle jerks that can occur alone or in combination with other types of seizures. Etymology: "Myo" refers to muscle. "Clonic" refers to alternating contraction and relaxation of muscles. "Seizure" refers to a sudden, uncontrolled electrical discharge in the brain.

N

Narrow Palpebral Fissures: The horizontal opening between the upper and lower eyelids, which can be reduced in size in certain genetic conditions. Etymology: "Narrow" refers to a reduced width. "Palpebral" refers to the eyelids. "Fissure" refers to a narrow opening or crack. Nasal Bridge: The bony part of the nose, which can be broad or flat in certain syndromes like Down Syndrome. Etymology: "Nasal" refers to the nose. "Bridge" refers to the bony structure that connects the two sides of the nose. Negative Reinforcement: The removal of an aversive stimulus following a behavior, which increases the likelihood of that behavior occurring again. Etymology: "Negative" refers to the removal of something. "Reinforcement" refers to a stimulus that increases the likelihood of a behavior. Neurofibromatosis: A genetic disorder causing tumors to form on nerve tissue, leading to skin changes and bone deformities. Etymology: "Neuro" refers to nerves. "Fibroma" refers to a fibrous tumor. "tosis" refers to a state or condition. Non-Invasive Prenatal Testing (NIPT): A method to screen for chromosomal abnormalities in a fetus using a blood sample from the mother. Etymology: "Non-invasive" refers to a procedure that does not involve entering the body. "Prenatal" refers to the period before birth. "Testing" refers to the process of examining or evaluating. Nuchal Translucency: The fluid-filled space at the back of a fetus's neck, measured during ultrasound screening to assess the risk of chromosomal abnormalities. Etymology: "Nuchal" refers to the back of the neck. "Translucency" refers to the ability to allow light to pass through.

O

Obsessive-Compulsive Disorder (OCD): A mental health disorder characterized by obsessive thoughts and compulsive behaviors. Etymology: "Obsessive" refers to persistent, unwanted thoughts. "Compulsive" refers to repetitive behaviors. "Disorder" refers to a disturbance or malfunction. Occipital Encephalocele: A neural tube defect where a portion of the brain protrudes through an opening in the skull. Etymology: "Occipital" refers to the back of the head. "Encephalocele" refers to a protrusion of brain tissue through an opening in the skull. Ocular Hypertension: Increased pressure in the eye that can lead to glaucoma if not managed properly. Etymology: "Ocular" refers to the eye. "Hypertension" refers to high blood pressure. Oculocutaneous Albinism: A condition characterized by a lack of pigment in the skin, hair, and eyes, affecting vision and increasing sensitivity to sunlight. Etymology: "Oculo" refers to the eye. "Cutaneous" refers to the skin. "Albinism" refers to a lack of pigment. Oligohydramnios: A condition characterized by a deficiency of amniotic fluid, which can lead to complications during pregnancy. Etymology: "Oligo" means "few" or "scanty." "Hydramnios" refers to an excess of amniotic fluid. Onasemnogene Abeparvovec (Zolgensma): A gene therapy for spinal muscular atrophy (SMA) that delivers a functional copy of the SMN1 gene to improve motor function. Etymology: "Onasemnogene" refers to the gene therapy. "Abeparvovec" refers to the specific type of virus used to deliver the gene. "Zolgensma" is the brand name. Ophthalmoplegia: Paralysis or weakness of the eye muscles. Etymology: "Ophthalmo" refers to the eye. "Plegia" refers to paralysis. Oral-Motor Dysfunction: Difficulty coordinating the muscles used for speech and swallowing. Etymology: "Oral" refers to the mouth. "Motor" refers to movement. "Dysfunction" refers to a disturbance or malfunction. Orthopedic Devices: Tools and equipment used to support or correct musculoskeletal deformities and improve mobility. Etymology: "Ortho" means "straight" or "correct." "Ped" refers to the foot. "Device" refers to a tool or instrument. Osteogenesis Imperfecta: A genetic disorder characterized by fragile bones that break easily. Etymology: "Osteo" refers to bone. "Genesis" refers to the origin or creation. "Imperfecta" means "imperfect" or "incomplete." Osteoporosis: A condition characterized by weakened bones, increasing the risk of fractures. Etymology: "Osteo" refers to bone. "Porosis" refers to a porous or spongy structure. Overcorrection: A procedure in ABA that involves having the individual correct the consequences of their behavior and then practice the correct behavior. Etymology: "Over" means "excessively" or "beyond." "Correction" refers to the act of setting something right.

P

Patau Syndrome (Trisomy 13): A genetic disorder caused by the presence of an extra chromosome 13, leading to severe intellectual disability and physical abnormalities. Etymology: Named after the German physician Klaus Patau who first described the syndrome in 1960. "Trisomy" refers to the presence of three copies of a chromosome. Patent Ductus Arteriosus (PDA): A heart defect where the ductus arteriosus fails to close after birth, which can lead to heart failure if untreated. Etymology: "Patent" means "open" or "unblocked." "Ductus arteriosus" refers to a blood vessel that connects the aorta and pulmonary artery in the fetus. "Arteriosus" refers to an artery. Pervasive Developmental Disorder (PDD): A group of disorders characterized by delays in the development of socialization and communication skills. Etymology: "Pervasive" refers to widespread or affecting all aspects. "Developmental" refers to the process of growth and change. "Disorder" refers to a disturbance or malfunction. Phenotype: The set of observable characteristics or traits of an individual resulting from the interaction of their genotype with the environment. Etymology: "Pheno" means "to show" or "to appear." "Type" refers to a category or classification. Phonological Disorder: A speech disorder characterized by difficulty in learning and organizing sounds in speech. Etymology: "Phono" refers to sound. "Logical" refers to the study of the structure and organization of language. "Disorder" refers to a disturbance or malfunction. Phelan-McDermid Syndrome: A genetic disorder characterized by developmental delay, intellectual disability, and absent or severely delayed speech. Etymology: Named after the American geneticists Susan Phelan and Michael McDermid who first described the syndrome in 1999. Positive Reinforcement: The presentation of a reinforcing stimulus following a behavior, which increases the likelihood of that behavior occurring again. Etymology: "Positive" refers to the addition of something. "Reinforcement" refers to a stimulus that increases the likelihood of a behavior. Polydactyly: The presence of extra fingers or toes, often associated with genetic conditions like Patau Syndrome. Etymology: "Poly" means "many." "Dactyl" refers to a finger or toe. Postnatal Testing: Testing performed after birth to diagnose genetic conditions, typically through physical examination and genetic analysis. Etymology: "Post" means "after." "Natal" refers to birth. "Testing" refers to the process of examining or evaluating. Prader-Willi Syndrome: A genetic disorder characterized by obesity, intellectual disability, and short stature, caused by the loss of function of specific genes on chromosome 15. Etymology: Named after the Swiss physicians Andrea Prader, Heinrich Willi, and Rolf Zbinden who first described the syndrome in 1956. Primary Ovarian Insufficiency (POI): A condition where the ovaries stop functioning normally before the age of 40, leading to reduced fertility and other health issues. Etymology: "Primary" refers to the initial or main cause. "Ovarian" refers to the ovaries. "Insufficiency" refers to a lack of something essential. Prompt: A cue or hint that is used to help an individual perform a desired behavior. Etymology: "Prompt" refers to something that encourages or causes an action. Proprioception: The body's ability to sense movement, action, and location, crucial for coordinated movement and balance. Etymology: "Proprio" means "one's own." "ception" refers to the process of perceiving or becoming aware. Prosopagnosia: The inability to recognize faces, often due to brain injury or a neurological disorder. Etymology: "Proso" means "face." "Gnosis" refers to knowledge or perception. Psoriasis: An autoimmune skin condition that causes rapid skin cell growth, leading to scaling and inflamed patches of skin. Etymology: "Psora" is a Greek word meaning "itch." "sis" refers to a state or condition. Pseudobulbar Affect: A condition characterized by episodes of uncontrollable laughter or crying, often seen in neurological disorders. Etymology: "Pseudo" means "false" or "imitation." "Bulbar" refers to the medulla oblongata, a part of the brainstem. "Affect" refers to emotion or feeling. Psychomotor Retardation: Slowing down of thought and physical movement, often associated with severe depression or neurological disorders. Etymology: "Psycho" refers to the mind. "Motor" refers to movement. "Retardation" refers to a slowing down or delay. Pulmonary Hypertension: High blood pressure in the arteries of the lungs, which can lead to heart failure if untreated. Etymology: "Pulmonary" refers to the lungs. "Hypertension" refers to high blood pressure.

Q

Quad Screen: A prenatal test that measures four substances in a pregnant woman's blood to assess the risk of certain genetic conditions in the fetus. Etymology: "Quad" means "four." "Screen" refers to a test or examination.

R

Ratio Schedules: Reinforcement schedules in which reinforcement is delivered after a certain number of responses. Etymology: "Ratio" refers to a relationship between two quantities. "Schedules" refers to a plan or pattern. Reactive Aggression: A form of aggression that is triggered by a perceived threat or provocation. Etymology: "Reactive" refers to a response to something. "Aggression" refers to hostile or violent behavior. Reciprocal Teaching: A strategy used in education to promote reading comprehension by having students take turns leading a discussion about a text. Etymology: "Reciprocal" refers to something that is mutual or shared. "Teaching" refers to the process of instructing or educating. Reinforcement: A stimulus that increases the likelihood of a behavior occurring again. Etymology: "Rein" refers to a controlling force. "Force" refers to a power or influence. Reinforcement Schedule: A rule that determines when reinforcement will be delivered. Etymology: "Reinforcement" refers to a stimulus that increases the likelihood of a behavior. "Schedule" refers to a plan or pattern. Renal Dysplasia: Abnormal development of the kidneys, which can lead to kidney failure. Etymology: "Renal" refers to the kidneys. "Dysplasia" refers to abnormal development. Retinitis Pigmentosa: A group of genetic disorders causing retinal degeneration and vision loss. Etymology: "Retinitis" refers to inflammation of the retina. "Pigmentosa" refers to the presence of pigment. Rett Syndrome: A genetic neurological disorder that occurs almost exclusively in females, leading to severe cognitive and physical impairments. Etymology: Named after the Austrian physician Andreas Rett who first described the syndrome in 1966. Risdiplam (Evrysdi): An oral medication for spinal muscular atrophy (SMA) that increases SMN protein levels by modifying SMN2 pre-mRNA splicing. Etymology: "Risdiplam" is the generic name of the medication. "Evrysdi" is the brand name.

S

Schizencephaly: A rare birth defect characterized by abnormal slits or clefts in the cerebral hemispheres of the brain. Etymology: "Schizo" means "split" or "divided." "Encephal" refers to the brain. Scoliosis: A lateral curvature of the spine that can occur in children and adults, often requiring monitoring and sometimes intervention. Etymology: "Scoliosis" is a Greek word meaning "crooked" or "bent." Secondary Reinforcer: A stimulus that has acquired reinforcing properties through association with a primary reinforcer. Etymology: "Secondary" refers to something that is not primary or original. "Reinforcer" refers to a stimulus that increases the likelihood of a behavior. Sensory Integration Therapy: A therapeutic approach that helps individuals with sensory processing issues by providing sensory experiences in a structured, supportive environment. Etymology: "Sensory" refers to the senses. "Integration" refers to the process of combining or merging. "Therapy" refers to the treatment of disease or injury. Sensory Processing Disorder: A condition where the brain has trouble receiving and responding to information that comes in through the senses, leading to challenges in performing everyday tasks. Etymology: "Sensory" refers to the senses. "Processing" refers to the way the brain handles information. "Disorder" refers to a disturbance or malfunction. Shaken Baby Syndrome: A serious brain injury resulting from forcefully shaking an infant or toddler. Etymology: "Shaken" refers to the act of shaking. "Baby" refers to an infant. "Syndrome" refers to a group of symptoms that occur together. Single Transverse Palmar Crease: A single crease that extends across the palm of the hand, commonly found in individuals with Down Syndrome. Etymology: "Single" refers to one. "Transverse" refers to a line that crosses at a right angle. "Palmar" refers to the palm of the hand. "Crease" refers to a fold or line. Skin Picking: A behavior that can be analyzed and treated using ABA principles. Etymology: "Skin" refers to the outer covering of the body. "Picking" refers to the act of removing something with the fingers. Smith-Lemli-Opitz Syndrome: A genetic disorder characterized by intellectual disability, behavioral problems, and physical abnormalities, caused by a defect in cholesterol synthesis. Etymology: Named after the American physicians David Smith, Robert Lemli, and John Opitz who first described the syndrome in 1964. Social Skills Training: A type of therapy that focuses on teaching individuals how to interact with others in a socially appropriate manner. Etymology: "Social" refers to the interactions between people. "Skills" refers to abilities or competencies. "Training" refers to the process of teaching or instructing. Speech Generating Devices (SGDs): Devices that produce spoken language, aiding communication for individuals with severe speech impairments. Etymology: "Speech" refers to the ability to speak. "Generating" refers to the process of creating or producing. "Device" refers to a tool or instrument. Spinocerebellar Ataxia: A group of genetic disorders characterized by progressive incoordination of gait and other voluntary movements. Etymology: "Spino" refers to the spine. "Cerebellar" refers to the cerebellum, a part of the brain that controls movement. "Ataxia" refers to a lack of muscle coordination. Spinal Muscular Atrophy (SMA): A genetic disorder characterized by weakness and wasting of the skeletal muscles due to the loss of motor neurons. Etymology: "Spinal" refers to the spine. "Muscular" refers to muscles. "Atrophy" refers to the wasting away of tissue. Stereognosis: The ability to perceive and recognize the form of an object using touch. Etymology: "Stereo" means "solid" or "three-dimensional." "Gnosis" refers to knowledge or perception. Stimulus Control: The ability for a stimulus to reliably elicit a specific behavior. Etymology: "Stimulus" refers to an event or object that elicits a response. "Control" refers to the ability to influence or direct. Strabismus: A condition in which the eyes do not properly align with each other when looking at an object. Etymology: "Strabismus" is a Greek word meaning "to squint" or "to look askance." Subependymal Nodules: Small, benign growths located near the ventricles of the brain, often associated with tuberous sclerosis. Etymology: "Sub" means "below." "Ependymal" refers to the lining of the ventricles of the brain. "Nodule" refers to a small, rounded mass. Succinic Semialdehyde Dehydrogenase Deficiency: A rare metabolic disorder that affects the breakdown of the neurotransmitter GABA, leading to a range of neurological symptoms. Etymology: "Succinic" refers to succinic acid, a chemical compound. "Semialdehyde" refers to a type of aldehyde. "Dehydrogenase" refers to an enzyme that removes hydrogen atoms. "Deficiency" refers to a lack of something essential. Switch Access: Technology that allows individuals with limited mobility to operate electronic devices using a single switch or other input method. Etymology: "Switch" refers to a device that controls the flow of electricity. "Access" refers to the ability to use or obtain something.

T

TBI (Traumatic Brain Injury): An injury to the brain caused by an external force, leading to temporary or permanent cognitive, physical, and emotional impairments. Etymology: "Traumatic" refers to an injury caused by an external force. "Brain" refers to the organ of thought and feeling. "Injury" refers to damage or harm. Tandem Walking: A type of walking where one foot is placed directly in front of the other, often used to assess balance and coordination. Etymology: "Tandem" refers to something that is arranged in a sequence. "Walking" refers to the act of moving on foot. Tay-Sachs Disease: A fatal genetic disorder that causes progressive destruction of nerve cells in the brain and spinal cord, primarily affecting infants. Etymology: Named after the British ophthalmologist Warren Tay and the American neurologist Bernard Sachs who first described the disease in 1881 and 1887, respectively. TEF (Tracheoesophageal Fistula): An abnormal connection between the trachea and esophagus, often present at birth, which can cause severe respiratory and feeding problems. Etymology: "Tracheo" refers to the trachea (windpipe). "Esophageal" refers to the esophagus. "Fistula" refers to an abnormal connection between two organs or cavities. Teaching: The process of instructing or educating. Etymology: "Teach" refers to the act of imparting knowledge or skills. Tetrasomy X: A rare chromosomal disorder where a female has four X chromosomes (48,XXXX), leading to a variable phenotype with physical, cognitive, and developmental challenges. Etymology: "Tetra" means "four." "Somy" refers to the number of chromosomes. "X" refers to the X chromosome. Time Sampling: A method of data collection in ABA that involves recording whether a behavior is occurring at specific points in time. Etymology: "Time" refers to a period of duration. "Sampling" refers to the process of taking a small sample. Token Economy: A behavior management system in ABA that uses tokens as a form of reinforcement. Etymology: "Token" refers to a symbol or object that represents something else. "Economy" refers to a system of managing resources. Trisomy 12p: A chromosomal disorder characterized by the presence of an extra copy of the short arm of chromosome 12, leading to developmental anomalies and physical malformations. Etymology: "Tri" means "three." "Somy" refers to the number of chromosomes. "12p" refers to the short arm of chromosome 12. Trisomy 18 (Edwards Syndrome): A chromosomal disorder caused by the presence of an extra chromosome 18, associated with severe intellectual disability, growth retardation, and multiple congenital anomalies. Etymology: Named after the British physician John H. Edwards who first described the syndrome in 1960. "Trisomy" refers to the presence of three copies of a chromosome. Trisomy 21 (Down Syndrome): A genetic disorder caused by the presence of an extra copy of chromosome 21, leading to intellectual disability, characteristic facial features, and various health issues. Etymology: Named after the British physician John Langdon Down who first described the syndrome in 1866. "Trisomy" refers to the presence of three copies of a chromosome. Trisomy 9: A rare chromosomal disorder characterized by the presence of an extra chromosome 9, leading to developmental delays, intellectual disability, and multiple physical anomalies. Etymology: "Tri" means "three." "Somy" refers to the number of chromosomes. "9" refers to chromosome 9. Tuberous Sclerosis Complex: A genetic disorder characterized by the growth of noncancerous tumors in various organs, including the brain, kidneys, heart, and skin. Etymology: "Tuber" refers to a swelling or bump. "Sclerosis" refers to hardening. "Complex" refers to a group of related things. Turner Syndrome: A chromosomal disorder in females caused by the complete or partial absence of one of the X chromosomes, leading to short stature, infertility, and various medical issues. Etymology: Named after the American physician Henry Turner who first described the syndrome in 1938.

U

UMLS (Unified Medical Language System): A set of files and software that brings together many health and biomedical vocabularies and standards to enable interoperability between computer systems. Etymology: "Unified" refers to the combination of different elements. "Medical" refers to medicine and healthcare. "Language" refers to a system of communication. "System" refers to a set of interconnected parts. Unconditioned Reinforcer: A stimulus that is naturally reinforcing, such as food, water, or sex. Etymology: "Unconditioned" refers to something that is not learned. "Reinforcer" refers to a stimulus that increases the likelihood of a behavior. Usher Syndrome: A genetic disorder causing hearing loss and progressive vision loss due to retinitis pigmentosa, often leading to deaf-blindness. Etymology: Named after the American ophthalmologist Charles Usher who first described the syndrome in 1914.

V

VEP (Visual Evoked Potential): An electrical potential recorded from the visual cortex in response to visual stimulation, used to assess the functional integrity of the visual pathways. Etymology: "Visual" refers to sight. "Evoked" refers to a response elicited by a stimulus. "Potential" refers to a measurable electrical difference. "VEP" is an abbreviation for "Visual Evoked Potential." Verbal Behavior: A type of behavior that is reinforced through social interaction. Etymology: "Verbal" refers to words or language. "Behavior" refers to the actions or responses of an organism. Verbal Operant: A unit of verbal behavior that is defined by its function. Etymology: "Verbal" refers to words or language. "Operant" refers to a behavior that is influenced by its consequences. Ventricular Septal Defect (VSD): A congenital heart defect characterized by an abnormal opening in the septum between the heart's ventricles, allowing blood to pass from the left to the right ventricle. Etymology: "Ventricular" refers to the ventricles of the heart. "Septal" refers to the septum, a wall that divides two chambers. "Defect" refers to an abnormality or flaw. Ventriculomegaly: An abnormal enlargement of the brain's ventricles, which can be associated with developmental delays and other neurological issues. Etymology: "Ventricular" refers to the ventricles of the brain. "Megaly" refers to enlargement.

W

WAGR Syndrome: A genetic condition characterized by Wilms tumor (a kidney cancer), Aniridia (absence of the iris), Genitourinary anomalies, and mental Retardation, caused by a deletion of genetic material on chromosome 11. Etymology: "WAGR" is an acronym for "Wilms tumor, Aniridia, Genitourinary anomalies, and mental Retardation." Walking: The act of moving on foot. Etymology: "Walk" refers to the act of moving on foot. Williams Syndrome: A genetic disorder characterized by developmental delays, cardiovascular problems, distinctive facial features, and a unique cognitive profile with strong language skills and an affinity for music. Etymology: Named after the American physician John C.P. Williams who first described the syndrome in 1961.

X

X-Linked Disorders: Genetic conditions that are associated with mutations in genes on the X chromosome, affecting males more severely due to the presence of only one X chromosome. Etymology: "X-linked" refers to genes located on the X chromosome. "Disorder" refers to a disturbance or malfunction. X-inactivation: A process in females where one of the X chromosomes in each cell is randomly inactivated to prevent an overdose of X-linked genes, with some genes escaping inactivation. Etymology: "X" refers to the X chromosome. "Inactivation" refers to the process of shutting down or deactivating.

Y

Y Chromosome Microdeletion: A genetic condition involving deletions of small segments of the Y chromosome, often leading to male infertility due to the loss of genes important for spermatogenesis. Etymology: "Y" refers to the Y chromosome. "Microdeletion" refers to the deletion of a small segment of DNA.

Z

Zellweger Spectrum Disorders: A group of genetic disorders caused by mutations affecting peroxisome biogenesis, leading to severe neurological impairment, liver dysfunction, and craniofacial abnormalities. Etymology: Named after the Swiss pediatrician Hans Zellweger who first described the syndrome in 1964.