ANALYSIS OF THE TESTIS-DETERMINING GENE SRY IN PATIENTS WITH XY GONADAL-DYSGENESIS

The sex-determining region of the Y chromosome (SRY) encodes a gene th at has many of the properties expected to the testis-determining facto r. XY gonadal dysgenesis is characterized by streak gonads in phenotyp ic females who lack the somatic abnormalities and short stature associ ated with Turner's syndrome, We have examined four patients with XY go nadal dysgenesis for the presence and absence of SRY and the DNA seque nce of the gene. The results showing that one was negative for SRY and another had a mutation within the gene have confirmed the etiological role of SRY in XY gonadal dysgenesis. However, the other two patients with short stature had apparently normal SRY. DNA sequencing of the S RY gene showed 100% nucleotide sequence identity with the reported clo ned sequence. Sex reversal in two of the present cases may be due to m utation at a locus other than SRY in the sex-determining pathway, a ge ne potentially involved in the determination of human sexual constitut ion.