Isochromosome Xq in Klinefelter syndrome: report of 7 new cases.

In this collaborative study we report on 2 prenatally and 5 postnatally diagnosed cases with a 47,X,i(Xq),Y chromosomal constitution. Excepting tall stature, the 5 adult patients showed all typical manifestations of Klinefelter syndrome. Taken together with previously reported cases, these data suggest that Klinefelter syndrome with isochromosome Xq has a favorable prognosis with normal mental development, and with normal-to-short stature. The prevalence of this Klinefelter variant is calculated to be between 0.3-0.9% in males with X chromosome polysomies.

Long arm deletions of the X chromosome and their symptoms: a new case (bp q24) and a short review of the literature.

The clinical and cytogenetic data from a 26-year-old female with del(X)(q24----ter) are reported. This breakpoint has not been described yet. Besides this report we give a comparative summary of 24 cases from the literature with different deletions of Xq.