A genetic syndrome in which a child usually experiences development delays and often has concurrent medical conditions including mental retardation, a small mouth, and short height.

Down Syndrome: "A congenital condition (Trisomy 21) that typically results in cognitive impairment." (p. 528, Lloyd, Fuller & Arvidson, 1998) Learn more at http://www.downsyndrome.com/ Click "BACK" on your browser to return to the previous page.

a chromosomal disorder with characteristic flat facial features, mental retardation and other congenital defects

Down syndrome is a chromosomal condition most commonly associated with mental retardation and poor muscle tone (hypotonia) during infancy. People with Down syndrome have increased risk for heart defects, digestive problems such as gastroesophageal reflux or celiac disease and hearing loss. In addition, some people with Down syndrome have reduced activity of the thyroid gland (hypothyroidism).

individuals that are trisomic for chromosome 21 due to nondisjunction of chromosome 21 during meiosis I. Syndrome is characterized by mental retardation and physical deformities.

A disorder caused by an abnormality at the 21st chromosome. One symptom of Down syndrome is mental retardation.

Due to trisomy 21. Chromosome 21 is the smallest of the "autosomes" (the non-sex chromosomes): trisomies of the other autosomes tend to be lethal at an earlier stage of embryonic or fetal development, and so are seen much more rarely. Diagnosis of Down's syndrome requires a karyotype, obtainable from pregnancy tissue by chorionic villus sampling (CVS) or amniocentesis. Screening for increased risk in pregnancy can be performed by triple screen or by looking for nuchal translucency at transvaginal ultrasound.

A genetic syndrome caused by the presence of an extra chromosome 21. For more information, visit The Parent Network

a genetic disease that is caused by an extra copy of chromosome 21.

a genetic disorder in which a person's cells have 1 too many chromosomes, causing moderate to severe mental handicap and a characteristic appearance

(down syn·drome) NOUN: Also Down's Syndrome. According to the National Down Syndrome Society, Down Syndrome is caused by the presence of an extra 21st chromosome. This additional genetic material alters the course of development and causes the characteristics associated with the syndrome. Those characteristics include a mild to moderate developmental disability, low muscle tone, short stature, and a flattened facial profile.

A genetic abnormality resulting from the presence of three copies of chromosome 21; individuals with this condition have characteristic physical and intellectual deficits.

A birth defect which is also called mongolism or trisomy-21, this causes multiple problems including developmental delay.

a form of mental retardation, associated with certain physical deformities, that is caused by an extra, third chromosome on the 21st pair. 355

Congenital condition characterized by certain physical malformations and some degree of mental retardation.

A chromosomal anomaly that often causes moderate to severe mental retardation, along with certain physical characteristics such as a large tongue, heart problems, poor muscle tone, and a broad flat bridge of the nose.

A congenital idiocy in which a child is born with slanting eyes, a broad short skull, and broad hands with short fingers. Caused by trisomy (triploidy) of the 21st human chromosome (autosome 21). Also called "mongolism."

A form of mental retardation generally caused by an extra chromosome. The child's IQ is usually less than 50, and the child has distinctive physical characteristics, most notably slanted eyes.

Also known as Down's syndrome. A congenital disorder that is usually caused by the presence of an extra 21st chromosome. The affected child will have mild to moderate mental retardation.

a congenital disorder caused by having an extra 21st chromosome; results in a flat face and short stature and mental retardation

a congenital disorder caused by caused by a chromosomal abnormality. It is characterized by mental deficiency and certain body abnormalities, including a flattened face, slanting eyes, a short nose, and broad hands and feet.

A genetic condition caused by an extra #21 chromosome (Trisomy 21), causing a variety of physical features and developmental delays.

This is a genetic disorder caused by the presence of an extra chromosome 21. (Called trisomy 21). Affected children have mental retardation and characteristic features of the body, face and limbs. Affected children also have many medical problems such has heart defects.

a condition of retardation and associated physical disorders caused by an extra chromosome. Each person has 23 pairs of chromosomes, one pair from each parent. A person with Down Syndrome has a 3rd chromosome on the 21st pair. This results are both mental and physical, and often include small eyes, and hands, protruding tongues, short necks and fingers. There are all different levels of the disorder, and the probability of a child being born with it increases as the mother's age increases; this is especially true as the mother becomes middle aged.

An inherited condition due to an extra chromosome 21, either as a third chromosome 21 or attached to chromosome 13, 14 or 15. Also called trisomy 21.

condition where an extra chromosome 21 causes distinctive physical features and mental retardation; also called trisomy 21. (This condition was formerly called "mongolism.")

A genetic condition usually caused by having an extra copy of the 21st chromosome. Also called trisomy 21.

A genetic disorder caused by the presence of an extra chromosome 21 and characterized by mental retardation, abnormal facial features, and medical problems such as heart defects. l J l l N l l Q l l l X l Y l

a genetic condition caused by extra genetic material (genes) from the 21st chromosome.

A chromosomal disorder (Trisomy 21) that cause physical and cognitive disabilities.

A chromosomal or genetic disorder caused by an extra copy of chromosome 21. For more information see the Factsheet on Down Syndrome. You may also visit the National Down Syndrome Society Website or the Down Syndrome Title Page Website.

A condition involving mental retardation and distinctive facial features which is due to an extra chromosome 21. This can be detected prenatally by chromosome analysis on fetal cells obtained by amniocentesis.

A common chromosome disorder due to an extra chromosome number 21 (trisomy 21). Down syndrome causes mental retardation, a characteristic face, and multiple malformations. Down syndrome is a relatively common birth defect. The chromosome abnormality affects both the physical and intellectual development of the individual. See the entire definition of Down syndrome

A genetic disorder caused by abnormal cell division during fetal development. Results in variable degrees of developmental delay, medical problems, and mental retardation.

congenital condition causing mental retardation and unique physical characteristics. Caused by an extra chromosome number 21.

A genetic disorder caused by extra chromosomes and characterized by mental retardation, medical problems and abnormal facial features

A chromosome disorder that causes mental retardation and a range of other physical problems, including infertility

Trisomy 21) The chromosomal abnormality characterized by an extra copy of chromosome 21. In rare cases this syndrome is caused by translocation. The extra copy can be free-lying, or can be attached to some other chromosome, most frequently number 14. Down syndrome can occur in mosaic. So that there is a population of normal cells and a population of trisomy 21 cells. Down syndrome is characterized by moderate to severe mental retardation, sloping forehead, small ear canals, flat bridged nose and short fingers and toes. One third of infants have congenital heart disease, and one third have duodenal atresia. (Both can be present in the same infant.) Affected people can survive to middle or old age. There is an increased incidence of Alzheimer disease in adults with Down syndrome.

trisomy 21; a genetic disorder in which an individual has an extra 21st chromosome, typically characterized by low muscle tone, cardiac problems, GI malformations and a distinct facial appearance

A congenital disease usually caused by an extra copy of chromosome 21 (trisomy 21).

When an extra copy of a chromosome is present when a baby develops. (A chromosome holds a cell’s genetic information for a person.) The extra chromosome usually causes mental and physical abnormalities.

A syndrome resulting from three (instead of the usual two) copies of chromosome 21.

An inherited condition caused by having an extra copy of chromosome 21. See aneuploidy.

The most common malformation caused by trisomy 21. Most of the patients (95%) have complete trisomy of chromosome 21; some have translocation or mosaic forms. The phenotype is diagnostic (short stature, characteristic facial appearance, mental retardation, brachydactyly, atlanto-axial instability, thyroid and white blood cell disorders). Congenital heart defects are frequent, atrioventricular septal defect and ventricular septal defect being the most common. Mitral valve prolapse and aortic regurgitation may be present. Down syndrome patients are prone to earlier and more severe pulmonary vascular disease than might otherwise be expected as a consequence of the lesions identified.

down syndrome is a chromosomal disorder. for some unexplained reason, one reproductive cell (egg or sperm) has an additional chromosome when united at conception. this extra chromosome is responsible for the specific physical characteristics common to down syndrome.

A common and easily recognizable chromosomal disorder caused by an error in cell division that results in the presence of an additional third chromosome 21 and presents mild to moderate mental retardation and associated medical problems.

The most common chromosomal abnormality, Down syndrome causes mild to severe mental retardation, as well as other physical problems such as heart defects.

This chromosomal disorder has an incidence of 1 in 660 newborns, making it one of the most common genetic syndromes. It is generally characterized by relatively small stature, mental deficiency, and various facial and other abnormalities.

A congenital disorder with a typical facial appearance, mental retardation and often other defects. It arises from an extra chromosome (Trisomy 21).

Caused by an extra chromosome number 21 resulting in mental retardation and other birth defects.

a group of symptoms including physical signs and developmental handicaps that are caused by abnormalities in chromosome 21, most often an unnecessary third copy. This condition is also called trisomy 21 because of the location of the genetic mutation.

An abnormal human phenotype, including mental retardation, due to a trisomy of chromosome 21; more common in babies born to older mothers.

A common genetic disorder in which there is an extra copy of chromosome number 21 (trisomy 21), resulting in mental retardation and physical malformations.

A genetic disorder caused by the presence of an extra chromosome and characterized by mental retardation, abnormal features of the face, and medical problems such as heart defects.

See Trisomy 21.

A disorder caused by the presence of an extra chromosome 21 and characterized by mental retardation and distinguishing physical features.

A common genetic disorder in which a child is born with forty-seven rather than forty-six chromosomes, resulting in developmental delays, mental retardation, low muscle tone, and other possible effects.

A combination of birth defects caused by the presence of an extra #21 chromosome.

Mild to moderate mental retardation due to a chromosomal (21) disorder; normally very loving, friendly and responsive. Down Syndrome

The most common type of chromosome abnormality caused by an extra number of 21st chromosomes; this abnormality results in varying degrees of mental retardation and other birth defects

Mental retardation that turns into Alzheimer's disease in later age.

Genetic condition associated with many vision problems including cataracts, eye turns, and the need for glasses.

Also called Trisomy 21 because affected individuals have three copies of chromosome 21 instead of two. The condition is characterized by mild to severe mental retardation and certain physical traits. Several tests are available during pregnancy to determine whether a baby will have Down’s syndrome. The most accurate tests, amniocentesis and CVS (chorionic villus sampling), count the baby’s chromosomes to determine the number of copies of chromosome 21.

A syndrome that causes slowed growth, abnormal facial features, and mental retardation. Down syndrome is caused by an extra copy of all or part of chromosome 21. Most individuals with Down syndrome develop Alzheimer’s disease in adulthood.

Down syndrome is a chromosomal condition (trisomy 21) caused by the presence of one extra chromosome. Individuals with Down syndrome experience slow physical and mental development and often exhibit certain identifiable physical characteristics, such as a round face, slanting eyes, and a small stature. People with Down syndrome usually function in the mild to moderate range of mental retardation and may experience health problems, most commonly hearing impairments and congenital heart disease.

Syndrome characterized by hypotonia, flat facial profile, upwardly slanted eyes, small low-set ears, short stature, mental retardation, small nose with a low nasal bridge, and spots at the periphery of the iris. Individuals with Down Syndrome have an extr

A genetic disorder (caused by the presence of an extra chromosome), which results in physical and mental abnormalities. Physical characteristics include a flattened face, widely spaced and slanted eyes, smaller head size and lax joints. Mental retardation is also typical, though there are wide variations in mental ability, behavior, and developmental progress. Possible related health problems include poor resistance to infection, hearing loss, gastrointestinal problems and heart defects.

Condition caused by chromosomal abnormality with a number of physical characteristics and varying degrees of mental retardation.

Caused by the extra chromosome #21, Down Syndrome is characterized by flattened facial features and mild to severe mental retardation.

A congenital birth defect that results in mental handicap.

Down syndrome or trisomy 21 (also Down's syndrome) is a genetic disorder caused by the presence of all or part of an extra 21st chromosome. It is named after John Langdon Down, the British doctor who first described it in 1866. The condition is characterized by a combination of major and minor differences in body structure.