ABSENCE OF THE TESTICULAR DETERMINING FACTOR GENE SRY IN XX TRUE HERMAPHRODITES AND PRESENCE OF THIS LOCUS IN MOST SUBJECTS WITH GONADAL-DYSGENESIS CAUSED BY Y-ANEUPLOIDY

OBJECTIVES: The purpose of our study was to discover whether the testicular determining factor gene SRY (sex-determining region on Y) is present or absent in XX true hermaphrodites and in subjects with gonadal dysgenesis caused by Y aneuploidy. STUDY DESIGN: We screened five XX true hermaphrodites and 24 subjects with gonadal dysgenesis caused by Y aneuploidy for the presence or absence of SRY. With the polymerase chain reaction technique, the sequence coding the 80 amino acid-conserved motif was amplified. The 0.9 kb HincII pY53.3 subclone, which covers the open reading frame of SRY, serves as a probe for Southern blot analysis. RESULTS: Test results for all five XX true hermaphrodites were negative for SRY. Conversely, 22 of the 24 individuals with 45,X/46,XY gonadal dysgenesis were positive for SRY, including the 10 subjects with only bilateral streak gonads. CONCLUSIONS: The absence of SRY in XX true hermaphrodites and the presence of SRY in 10 subjects with 45,X/46,XY constitution who harbored only bilateral streak gonads seem to indicate that multiple genes are involved in gonadal differentiation.