MOLECULAR-DETECTION OF Y-DNA SEQUENCES IN PATIENTS WITH TURNERS-SYNDROME

The presence of Y-chromosome material in the genome of phenotypic fema les has been associated with an increased risk of developing gonadal t umors. To assess whether DNA sequences of the Y-chromosome are present in the genome of individuals with gonadal dysgenesis and clinical fea tures of Turner's syndrome, we have studied three patients with 45, X/ 46, X, + mar chromosome complement, and two Turner patients with 45, X /46, XY and 45, X karyotypes who served as positive and negative contr ols, respectively. Molecular detection of Y-DNA sequences was done by DNA-DNA hybridization using the specific probes pY97 and pDP1007 as we ll as by polimerase chain reaction. The results revealed that the mark er chromosome of one of the patients contained DNA sequences from the centromeric region of the Y-chromosome in a manner similar to that fou nd in the 45, X/46, XY patient and in the male control; the gene ZFY w as negative in this patient, and was probably lost when the ring chrom osome was formed. In contrast, the ring chromosomes of the other two p atients did not exhibit the presence of Y-chromosome material. The res ults were interpreted as demonstrating the Y-chromosome origin of the ring marker in one patient with gonadal dysgenesis, and suggest an X-c hromosome origin of the ring markers in the other two patients. These data further underline the relevance of practicing molecular studies i n these disorders which may help to determine appropriate therapeutic strategies.