An isodicentric X chromosome with gonadal dysgenesis in a lady without prominent somatic features of Turner's syndrome. A case report.

Isodicentric X chromosomes in general have phenotypes characteristic of the resultant X deletions. Gonadotropin levels in Turner's syndrome (TS) girls are high, but have a normal biphasic pattern. Here, we report a 21-year-old lady with primary amenorrhea. Clinical examination revealed a short neck but no other typical stigmata of Turner's syndrome. The levels of gonadotropin were not raised to post-menopausal levels. A chromosome study showed a 45,X/46,X,idic(X)(q22) karyotype. She was diagnosed as having Turner's syndrome.