Klinefelter-Syndrom mit dem Chromosomensatz 47, XXpiY

Isodicentric Xq in Klinefelter syndrome

“…This has suggested the existence of a specific isochromosome Xq KS presenting with a lack of height increase. This observation seems substantiated by several reported patients [Donlan et al, 1987;Gardiner et al, 1978;Geneix et al, 1983;Kalousek et al, 1978;Kleczkowska et al, 1988;Ponzio et al, 1980;Richer et al, 1989;Trunca et al, 1979;Zang et al, 1969; Table I], although this point should be judged comparing the patients to their parents and sibs. In fact, a nonmosaic i(Xq) KS man [Kleczkowska et al, 19881 with an increased height (198 cm) has questioned the existence of a distinct phenotype associated with this rare cytogenetic variant of KS [F'ryns et al, 19901. We report here the clinical, hormonal, and cytogenetic data of a man with KS due to an isodicentric Xq, a hitherto undescribed chromosome complement which widens the genotypic spectrum of this syndrome.…”

“…The present patient with an idic(Xq) and KS had duplication of Xp and partial duplication of Xq. This abnormal chromosome could have originated from an isochromatid break in the G2 phase, followed by fusion of the broken sister chromatids or from breakage in the G1 phase Zang et al, 1969Gardiner et al, 1978McDermott, 1978Kalousek e t al., 1978Trunca et al, 1979Ponzio et al, 1980Geneix et al, 1981Donlan e t al., 1987Kleczkowska et al, 1988Kleczkowska e t al., 1988Richer et al, 1989 and fusion of broken ends during or after replication [Dewalds, 19831. This patient had tall stature similar to that of a few known KS patients with a structurally rearranged extra X chromosome. He has three copies of Xp and three copies of Xq.…”

Unravelling the parental origin and mechanism of formation of the 47,XY,i(X)(q10) Klinefelter karyotype variant

“…Here, we report on the parental origin and mechanism of formation of the derivative X chromosome and its normal homologue in an infertile man with Klinefelter syndrome and a 47,XY,i(X)(q10) karyotype, and review the phenotype of the 18 adults (McDermott A., personal communication, 1978) (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15) with this karyotype as reported in the literature.…”