Ullrich-Turner syndrome: Relevance of searching for Y chromosome fragments

Forty consecutive patients with Ullrich-Turner syndrome (UTS) were followed -up and investigated for the presence of Y chromosome fragments in their ge nomes, We used the polymerase chain reaction (PCR) to detect SRY (sex-deter mining region on the Y chromosome) and the sequence-tagged sites (STS) sY57 , sY59, sY85, sY94, sY124 and sY157 - which correspond to regions 3C (sY57 and 59), 5C, 5G, 5P, and 6F, respectively, of the Y chromosome searching fo r Y fragments that could bear the putative locus (loci) for gonadoblastoma (GBY). It has been shown that the presence of GBY greatly increases the ris k of dysgenic gonads to undergo malignant transformation. Among our 40 pati ents, we found Y-derived sequences - including SRY and the region spanning from sY57 to sY94 - in two. These two patients had a marker chromosome dete cted by conventional cytogenetic analysis (45,X/46,X + mar). Their gonads w ere excised and found to be streaks. In one of the patients, we found foci of primitive sex cords (amidst the gonadal stroma), oviducts and Wolffian r emnants. Fluorescence in situ hybridization (FISH) did not show Y chromosom e material in her gonad-derived fibroblasts, The other girl had hyperplasti c Leydig cells in the gonadal stroma, oviducts and Wolffian remnants, with signs of epididymal differentiation. PCR assays performed on DNA extracted from paraffin-embedded gonadal tissue were negative for SRY sequences in bo th patients. These findings show that all UTS patients should be examined f or Y chromosome material, and that positive cases should have their dysgeni c gonads excised due to the high risk of malignancy.