Other specified trisomies and partial trisomies of autosomes

This code signifies the presence of an extra copy of a portion of an autosome, or an entire extra autosome, that is not specifically classified elsewhere. These genetic conditions result from an abnormal number of chromosomes, leading to a range of developmental and physical anomalies depending on the specific chromosome(s) involved and the extent of the duplication.

Assign this code when documentation confirms a trisomy or partial trisomy of an autosome that does not have a more specific ICD-10-CM code. This typically applies to rare or newly identified chromosomal abnormalities. Supporting documentation includes genetic testing results (e.g., karyotype, FISH, microarray) and clinical geneticist reports detailing the specific chromosomal aberration.

• Do not use this code if a more specific trisomy code (e.g., Down syndrome, Patau syndrome, Edwards syndrome) is available.
• Ensure the documentation clearly specifies "other specified" or "partial" trisomy of an autosome to justify this code.
• Sequence this code as a primary diagnosis when it is the reason for the encounter, or as a secondary diagnosis when it is an underlying condition impacting care.