Familial X;Y translocation with distinct phenotypic consequences: Characterization using FISH and array CGH

X;Y translocation is a relatively rare event in humans. Analyzed cytogenetically, the majority of these aberrations have breakpoints at Xp22 and Yq11. Females with t(X;Y)(p22;q11) are phenotypically normal except for short stature, while the males may have abnormalities. Aberrations that lead to nullisomy of the deleted region and complete loss of the respective genes have been recognized as a cause of variable contiguous gene syndromes in males. The phenotype depends on the extent and position of the deletion showing the variable association of apparently unrelated clinical manifestations such as ichthyosis, chondrodysplasia punctata, hypogonadotropic hypogonadism with anosmia, ocular albinism, short stature, and mental retardation. In addition, some patients have been reported with symptoms of attention deficit hyperactivity disorder. The extent of terminal Xp deletions is limited by the presence of male lethal genes in Xp22.2 at about 10-11 Mb from the telomere. The deletions in the majority of viable reported male patients extend to the STS (∼7.0 Mb) or to the KAL1 (∼8.5Mb) loci. We present a clinical, cytogenetic, FISH, and array CGH study of a family with an Xp;Yq translocation. The chromosomal status is also discussed in the light of their phenotypic traits. The final karyotypes of the patients were designated as: Patient 1: 46,Y,der(X),t(X;Y)(p22;q12).ish der(X)(Xpter-,DXZ1+, Xqter+)mat.arr cghXp22.31p22.33(RP11-60P14→RP13-391G2) x0;arr cgh Yq11.221qter (RP11-235I1→RP11-270H4)x2. Patient 2: 46,X,der(X),t(X;Y)(p22;q12).ish der(X)(Xpter-,DXZ1+, Xqter+)mat.arr cghXp22.31p22.33(RP11-60P14→RP13-391G2) x1;arr cgh Yq11.221qter (RP11-235I1→RP11-270H4)x1.