Karyotype 46, X iso (Xq)

This code identifies Turner syndrome caused by an isochromosome Xq, meaning the short arm (p) of one X chromosome is missing, and the long arm (q) is duplicated. This specific chromosomal abnormality results in a 46,X,i(Xq) karyotype, leading to the characteristic features of Turner syndrome.

Use this code when genetic testing, typically a karyotype analysis, confirms the presence of an isochromosome Xq in a patient presenting with signs and symptoms of Turner syndrome. Documentation must clearly state the specific chromosomal finding of 46,X,i(Xq) or Karyotype 46, X iso (Xq).

• Ensure the documentation explicitly states "isochromosome Xq" or "i(Xq)" to differentiate from other Turner syndrome variants.
• Do not use this code for other forms of Turner syndrome, such as monosomy X (45,X) or mosaicism, which have different specific codes.
• This code is a primary diagnosis for the genetic condition; consider additional codes for associated clinical manifestations (e.g., congenital heart defects, renal anomalies).