Turner Syndrome With Isochromosome Structural Abnormalities: A Case Report

Abstract

Turner syndrome (TS) is the most common cause of short stature and delayed puberty in females. Approximately half of the patients have the classic form with a genotype of 45,XO, one-fourth of patients have different mosaic forms, and the remaining one-fourth have structural abnormalities on the X chromosome. Among the structural abnormalities, the most common is isochromosome Xq. Females with structural variants of TS can present with delayed menarche, amenorrhea, and infertility rather than classic manifestations of TS.This study describes two rare variants of TS. One was a structural abnormality on the X chromosome, 46X,iso(Xq), and the other involves a mosaic variety of TS, including isochromosome X in the form of 45,XO/46X,iso(Xq). Both patients presented with short stature and secondary amenorrhea without classic manifestations of TS.In TS with or without mosaicism, the frequency of isochromosomes is reported to be about 15% to 18%. Owing to the absence of classical manifestations of TS, diagnosis may be delayed or missed. Therefore, females of short stature with secondary amenorrhea should be evaluated for rare variants of TS by chromosomal analysis.

Turner syndrome with isochromosome Xq as a cause of granulomatous hepatitis: a case report

“…The remaining cases encompass structural abnormalities of the X chromosome. Isochromosome Xq, like in our case, is the most prevalent among the structural X chromosome abnormalities 1 and is the underlying cause in 10% of the cases of TS 10 .…”

“…Turner syndrome (TS) is a rare genetic condition with multisystem involvement caused by absence or insufficiency of the second sex chromosome. Half of the affected girls have 45, X monosomy while the remainder have mosaicism or structural anomalies of the X chromosome 1 . Genotype 46, X,i(Xq) is the most prevalent among the structural X chromosome abnormalities, accounting for 10% of cases 2 .…”