A Case of Swyer Syndrome Which showed a Positive SRY Gene in Peripheral Blood and Gonad

말초혈액과 생식선에서 SRY유전자 양성을 보인 Swyer증후군 1례

Male sexual differentiation involves a cascade of events initiated by the presence on the Y chromosome of the of the SRY (sex determining region of Y chromosome) gene, which causes the indifferent gonad to develop into a testis. Hormonal products of the testis, predominantly testosterone and Mullerian inhibiting subtance (MIS), then control the sexual differentiation of the developing fetus. SRY is a transcription factor; however, target genes for its action have yet to be identified, because the DNA recognition sequence for SRY is found in many genes. Therefore the study of intersex disorders is being used to identify other genes active in the pathway of sexual differentiation. Patients with 46,XY gonadal dysgenesis, or Swyer's syndrome, have streak gonads, normal stature, and a sexually infantile phenotype with Mullerian structures present. The inheritance is usually sporadic but can be autosomal dominant or X-linked recessive. Unlike 45,X patients, stigmata of Turner syndrome are rare. As many as 20 to 30% of patients are at risk for malignant gonadal tumor formation and should undergo gonadectomy soon after the diagnosis is made. We have experienced a case of Swyer syndrome which showed a positive SRY gene in peripheral blood and gonad. So we report this case with a brief review of literatures.