A “balanced” Y;16 translocation associated with Turner-like neonatal lymphedema suggests the location of a potential anti-Turner gene on the Y chromosome

Abstract

A male patient with Turner-like hydrops in the newborn period (Bonnevie-Ullrich syndrome) was studied. The karyotype was 46, X, t(Y;16)(q11.2;q24) in 100 cells. Chromosome painting with the heterochromatic Y chromosome-specific long arm repeat DYZ2 disclosed that all the hybridization was on the derivative 16. This was confirmed by chromosome painting with DYZ1, the other major Y long arm heterochromatic repeat, and DYZ3, the Y alphoid, centromeric repeat which showed chromosomal separation of the 2 stained regions. To further localize the breakpoint, FISH was performed using individual YACs from a Y-YAC contig (Foote et al., 1992). This disclosed two YACs (yOX111 and yOX123) which hybridized to both the Y and der16 chromosomes. The YACS spanning the translocation breakpoint region were located just proximal to the Y heterochromatin boundary. The recent discovery of a candidate gene for the azoospermia factor (AZF) in this region (Ma et al., 1993) suggests the possibility that there are several Y-expressed genes adjacent to the heterochromatin boundary (as there are near the pseudoautosomal boundary) which may include a gene involved with lymphedema which is disrupted by the translocation in this patient.