U.S. flag

An official website of the United States government


Send to:

Choose Destination

Down Syndrome

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, single transverse palmar 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)

Year introduced: 1993

PubMed search builder options


Tree Number(s): C10.597.606.360.220, C16.131.077.327, C16.131.260.260, C16.320.180.260

MeSH Unique ID: D004314

Entry Terms:

  • Syndrome, Down
  • Mongolism
  • 47,XY,+21
  • Trisomy G
  • 47,XX,+21
  • Down's Syndrome
  • Downs Syndrome
  • Syndrome, Down's
  • Trisomy 21
  • Trisomy 21, Mitotic Nondisjunction
  • Down Syndrome, Partial Trisomy 21
  • Partial Trisomy 21 Down Syndrome
  • Trisomy 21, Meiotic Nondisjunction

Supplemental Content

Loading ...