Definitions for down syndrome
This page provides all possible meanings and translations of the word down syndrome
mongolism, mongolianism, Down's syndrome, Down syndrome, trisomy 21(noun)
a congenital disorder caused by having an extra 21st chromosome; results in a flat face and short stature and mental retardation
Condition caused by a chromosomal excess, whereby the patients bear a certain resemblance to the Mongoloid race, such as a small head and tilted eyelids.
Origin: Named after John L.H. Langdon-Down (1828-1896), an English physician who described it in the late 1800s. The term was first used in 1961.
Down syndrome or Down's syndrome, also known as trisomy 21, is a genetic disorder caused by the presence of all or part of a third copy of chromosome 21. Down syndrome is the most common chromosome abnormality in humans. It is typically associated with a delay in cognitive ability and physical growth, and a particular set of facial characteristics. The average IQ of young adults with Down syndrome is around 50, whereas young adults without the condition typically have an IQ of 100. A large proportion of individuals with Down syndrome have a severe degree of intellectual disability. Down syndrome is named after John Langdon Down, the British physician who described the syndrome in 1866. The condition was clinically described earlier by Jean Etienne Dominique Esquirol in 1838 and Edouard Seguin in 1844. Down syndrome was identified as a chromosome 21 trisomy by Dr. Jérôme Lejeune in 1959. Down syndrome can be identified in a newborn by direct observation or in a fetus by prenatal screening. Pregnancies with this diagnosis are often terminated. The CDC estimates that about one of every 691 babies born in the United States each year is born with Down syndrome.
U.S. National Library of Medicine
A chromosome disorder associated either with an extra chromosome 21 or an effective trisomy for chromosome 21. Clinical manifestations include hypotonia, short stature, brachycephaly, upslanting palpebral fissures, epicanthus, Brushfield spots on the iris, protruding tongue, small ears, short, broad hands, fifth finger clinodactyly, Simian crease, and moderate to severe MENTAL RETARDATION. Cardiac and gastrointestinal malformations, a marked increase in the incidence of LEUKEMIA, and the early onset of ALZHEIMER DISEASE are also associated with this condition. Pathologic features include the development of NEUROFIBRILLARY TANGLES in neurons and the deposition of AMYLOID BETA-PROTEIN, similar to the pathology of ALZHEIMER DISEASE. (Menkes, Textbook of Child Neurology, 5th ed, p213)
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