According to the ICD-10 (International Statistical Classification of Diseases and Related Health Problems), Down syndrome is classified as follows, depending on the suspected etiology (cause):
- ICD-10 Q90.0: Trisomy 21, meiotic nondisjunction (Free trisomy 21).
- ICD-10 Q90.1: Trisomy 21, mosaic (mitotic non-disjunction).
- ICD-10: Q90.2 trisomy 21, translocation
- ICD-10: Q90.9 Down syndrome, unspecified.