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Variant Klinefelter syndrome 47,X,i(X)(q10),Y and normal 46,XY karyotype in monozygotic adult twins
Author(s) -
Stemkens D.,
Broekmans F.J.,
Kastrop P.M.M.,
Hochstenbach R.,
Smith B.G.,
Giltay J.C.
Publication year - 2007
Publication title -
american journal of medical genetics part a
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.064
H-Index - 112
eISSN - 1552-4833
pISSN - 1552-4825
DOI - 10.1002/ajmg.a.31856
Subject(s) - karyotype , monozygotic twin , isochromosome , male infertility , x chromosome , genetics , hypergonadotropic hypogonadism , klinefelter syndrome , infertility , biology , medicine , endocrinology , chromosome , gene , pregnancy , hormone
Klinefelter syndrome (KS; 47, XXY) is characterized by increased body height, hypergonadotrophic hypogonadism, and infertility. We describe a patient with a variant KS (47,X,i(Xq),Y) who has a twin brother with a 46,XY karyotype. Molecular studies showed that the twins were monozygotic. The presence of an isochromosome Xq in one of two monozygotic twins allows precise investigation of its phenotypic effect. The patient was somewhat shorter (3.5 cm) and had a smaller volume of the testes (8 vs. 18 ml) as compared to his twin brother. Furthermore he had increased gonadotrophin levels and an extreme oligoasthenoteratozoospermia (OAT). These data support the view that genes on Xp cause increased body height and genes on Xq cause infertility in KS. To our knowledge this is the first report on a heterokaryotypic monozygotic twin with a variant KS. © 2007 Wiley‐Liss, Inc.