Down Syndrome
47,XX,+21
47,XY,+21
Down Syndrome, Partial Trisomy 21
Down's Syndrome
Downs Syndrome
Mongolism
Partial Trisomy 21 Down Syndrome
Syndrome, Down
Syndrome, Down's
Trisomy 21
Trisomy 21, Meiotic Nondisjunction
Trisomy 21, Mitotic Nondisjunction
Trisomy G
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 INTELLECTUAL DISABILITY. 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)