Down syndrome

Also known as: Trisomy 21

Most common chromosomal cause of intellectual disability.

Medical specialty: Pediatrics
Subspecialty: Pediatrics / Pediatric genetics
Sex & age distribution: Male: affected; Female: affected, equal; Children: yes, congenital
Gene(s) involved: None recorded

Etiology & mechanism

Extra copy of chromosome 21.

Gene(s) involved (0)

No gene recorded.

Symptoms & signs (6)

congenital heart defectsflat facieshypotoniaintellectual disabilitysingle palmar creaseupslanting palpebral fissures

SyndromeScope — educational reference. Content is model-generated and not clinically verified; always confirm against OMIM, Orphanet and GeneReviews before clinical use.