From parent levels

ChapterXVIICongenital malformations, deformations and chromosomal abnormalitiesOpen

Exclusions

inborn errors of metabolism (E70-E90)

BlockQ90-Q99Chromosomal abnormalities, not elsewhere classifiedOpen

Q90

CategoryBlock Q90-Q99 Chapter XVII

Down syndrome

Subcategories

Q90.0Trisomy 21, meiotic nondisjunction

Q90.1Trisomy 21, mosaicism (mitotic nondisjunction)

Q90.2Trisomy 21, translocation

Q90.9Down syndrome, unspecified

Parent: Q90-Q99 Chromosomal abnormalities, not elsewhere classified