Delayed diagnosis in a case of secondary amenorrhea caused by a long arm isochromosome--X; i(xq).

Secondary amenorrhea was observed in a 27-year-old woman with a structurally abnormal isochromosome--X, i(Xq), in all cells analyzed. The apparent phenotypical variability that may be observed in subjects with functional monosomy for the short arm of X, must be taken into consideration when patients with amenorrhea are clinically investigated. A correct, and early diagnosis of the etiology of the dysgenetic state of the gonads may only be obtained by accurate cytogenetic investigations, i.e., by utilizing various modern banding techniques.