Rare rearrangements: A "jumping satellite" in one family and autosomal location of the SRY gene in an XX male

Abstract

A satellited short arm of the Y chromosome (Yps) is rare. Only one de novo case of Yps has been documented. Here we report the prenatal diagnosis of Yps in a male fetus with a karyotype, 46,XYps. Family chromosome study showed that the father and a sister had a satellited short arm of the X chromosome (Xps). A phenotypically normal male child with the Yps was delivered. This is the first familial case showing a satellite "jumping" from Xp to Yp.Wepropose that it resulted froma crossover within the pseudoautosomal region 1(PAR1)onthe distalXpandYpduring paternal meiosis. In addition to the rare translocation mentioned above, relocation of the SRY gene onto an autosome in XX males is also a rare event. Herein we report a phenotypically normal male fetus with a 46,XX karyotype. Fluorescence in situ hybridization (FISH) study showed that the SRY locus had been transferred to the terminal short arm of a chromosome 3. The terminal short arm deletion of this chromosome 3 was also confirmed by FISH study with a subtelomeric probe and the breakpoint of the terminal deletion was estimated between 446 and 664 kb from the 3p telomere by real-time qPCR study with a gene sequence and STS markers in this region. A healthy boy was delivered at 37 weeks of gestation. At 1-year follow-up, the child's growth pattern and development were appropriate for age. © 2009 Wiley-Liss, Inc.