Clinical and Cytogenetical Studies in Female Gonadal Dysgenesis and Their Bearing on the Cause of Turner’s Syndrome

Abstract

Clinical and chromosomal studies are reported for 30 female patients selected because they show at least one of the characteristic features of Turner’s syndrome. Exploratory laparotomy has been performed in eight patients, and culdoscopy in two others. Seven patients have an XO sex chromosome constitution, eight have XO/XX mosaicism, two have probable XO/XX/XXX mosai-cism, one has XX1, five have XO/XXi mosaicism, one has a presumptive deletion of the long arm of an X chromosome, two have small structural X or Y chromosome aberrations, one has XO/XY mosaicism and three have an apparently normal XX karyotype. Xg grouping in one XO patient and her parents reveals that the X chromosome may be maternally derived, and similar studies in one X isochromosome-X patient suggest that the isochromosome-X may be paternally derived. Parental age was found to be normal. Sex chromatin findings in the patients with an isochromosome-X, and in a patient with an X-deletion, confirm that the structurally abnormal X forms the sex chromatin body. Karyotype-phenotype correlations in these, and in previously reported patients, support the hypothesis that the usual cause of Turner’s syndrome and its variants is variable deficiency of the X and Y chromosomes, due both to mosaicism and to deletion involving postulated homologous loci. “Streak” gonads are the usual consequence of a large deficiency of any part of the X, but the marked short stature and associated stigmaa of Turner’s syndrome are only observed in cases where the deficiency includes the short arm of the X (including the pairing segment) or part of the Y. The karyotype-phenotype correlations support the concept that a part of the short arm of both X chromosomes is genetically active in human female somatic cells.

Controlling elements in the mouseX-chromosome: I. Interaction with the X-linked genes

“…in man aneuploidy of the X is associated with abnormal phenotypes. The line of thought has been that there might be a region of the X, both in man (Ferguson-Smith et al 1964;Ferguson-Smith, 1965) and in the mouse (Russell, 1963), that is free of the inactivation process, or that some loci may not be inactivated (Beutler, 1964). The results of the present experiments suggest quite a different level of incomplete inactivation, for it pertains to loci that are clearly subject to inactivation.…”

Two Cases of Gonadal Dysgenesis with Typical Female Chromosomal Pattern

“…In a recent publication, Ferguson-Smith [14] tried to correlate karyotypes and phenotypes of patients with gonadal dysgenesis. He concluded th at complete Turner's syndrome is due to monosomy of loci on the short arm of the X chromosome, which are homologous with certain loci of the short arm of the Y chromosome.…”

“…[2]. This variability led Ferguson-Smith, in a recent study, to propose a new hypothesis on homologous seg ments of the X and Y chromosome to explain karvotvpe-phcnotvpc relationships [14], It is the purpose of this communication to present two further patients with gonadal dysgenesis and normal female karyotype in all examined tissues, including fibroblasts from ovarian streaks. At the time of her birth, her father was 22 and her mother 19 years old.…”

Reduced fertility in women with X chromosome abnormality

“…Short stature and the characters of Turner's syndrome are believed to result from monosomy of the X short arm (Ferguson-Smith et al 1964, Goldman et al 1982. Short stature and the characters of Turner's syndrome are believed to result from monosomy of the X short arm (Ferguson-Smith et al 1964, Goldman et al 1982.…”