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A novel frameshift mutation in the 5α-reductase type 2 gene in Korean sisters with male pseudohermaphroditism

2006; Elsevier BV; Volume: 85; Issue: 3 Linguagem: Inglês

10.1016/j.fertnstert.2005.08.052

1556-5653

Sung Hoon Kim, Kun Suk Kim, Gu Hwan Kim, Byung Moon Kang, Han Wook Yoo,

Urological Disorders and Treatments

ObjectiveTo describe two cases of 5α-reductase deficiency and the identification of a novel frameshift mutation in this sibling pair.DesignCase report.SettingAn adolescent clinic at a university hospital.Patient(s)A 14-year-old girl and her younger sister, who presented with primary amenorrhea, deepening of the voice, and clitoromegaly.Intervention(s)Deoxyribonucleic acid was extracted from peripheral blood, and 8 exons of the androgen receptor gene and 5 exons of the steroid 5α-reductase type 2 gene (encoded by SRD5A2 gene) were amplified by polymerase chain reaction and subjected to sequence analyses.Main Outcome Measure(s)Genetic diagnosis of 5α-reductase deficiency.Result(s)There was no evidence of a genetic abnormality in the 8 screened exons of the androgen receptor gene, but exon 4 of the SRD5A2 gene showed a novel homozygous deletion of the thymine at nucleotide position c.655 (c.655delT), leading to a frameshift mutation predicted to result in an abnormally long protein with an extended termination signal.Conclusion(s)The molecular characterization of the mutation can be a relevant tool for a correct diagnosis of 5α-reductase deficiency. To describe two cases of 5α-reductase deficiency and the identification of a novel frameshift mutation in this sibling pair. Case report. An adolescent clinic at a university hospital. A 14-year-old girl and her younger sister, who presented with primary amenorrhea, deepening of the voice, and clitoromegaly. Deoxyribonucleic acid was extracted from peripheral blood, and 8 exons of the androgen receptor gene and 5 exons of the steroid 5α-reductase type 2 gene (encoded by SRD5A2 gene) were amplified by polymerase chain reaction and subjected to sequence analyses. Genetic diagnosis of 5α-reductase deficiency. There was no evidence of a genetic abnormality in the 8 screened exons of the androgen receptor gene, but exon 4 of the SRD5A2 gene showed a novel homozygous deletion of the thymine at nucleotide position c.655 (c.655delT), leading to a frameshift mutation predicted to result in an abnormally long protein with an extended termination signal. The molecular characterization of the mutation can be a relevant tool for a correct diagnosis of 5α-reductase deficiency.