Mosaicism, 45, X/46, XX or XY

This code describes a form of Turner syndrome mosaicism where some cells have a 45, X karyotype (missing one sex chromosome), while other cells have a normal 46, XX (female) or 46, XY (male) karyotype. This chromosomal anomaly can lead to a spectrum of clinical features, including short stature, gonadal dysgenesis, and various congenital anomalies.

Use this code when documentation confirms a diagnosis of mosaicism involving a 45, X cell line alongside a normal 46, XX or 46, XY cell line, typically identified through cytogenetic analysis. This diagnosis is often made in individuals presenting with features suggestive of Turner syndrome, ambiguous genitalia, or infertility.

• Ensure the documentation explicitly states the specific mosaic karyotype (45, X/46, XX or XY) to differentiate from other forms of Turner syndrome or sex chromosome mosaicism.
• Code any associated congenital anomalies or clinical manifestations separately, as appropriate.
• Do not use this code for classic Turner syndrome (45, X) without documented mosaicism.