Partial trisomy

This code describes a genetic condition where an individual has three copies of only a segment of a chromosome, rather than an entire extra chromosome. This chromosomal abnormality leads to an imbalance in genetic material, often resulting in a range of developmental and physical anomalies depending on the specific chromosome segment involved.

Use this code when documentation clearly indicates a diagnosis of partial trisomy identified through genetic testing, such as karyotyping or microarray analysis. This diagnosis is typically made prenatally or in infancy when characteristic features or developmental delays are observed. Documentation should specify "partial trisomy" without mention of an unbalanced translocation as the cause.

• Do not use this code if the partial trisomy is explicitly stated as being due to an unbalanced translocation; instead, refer to the Excludes1 note.
• Ensure the physician's documentation clearly states "partial trisomy" and not a full trisomy (e.g., Trisomy 21).
• Always review genetic testing reports and physician notes for the precise nature of the chromosomal abnormality.