A novel frameshift mutation in the 5alpha-reductase type 2 gene in Korean sisters with male pseudohermaphroditism.
OBJECTIVE
To describe two cases of 5alpha-reductase deficiency and the identification of a novel frameshift mutation in this sibling pair.


METHODS
Case report.


METHODS
An adolescent clinic at a university hospital.


METHODS
A 14-year-old girl and her younger sister, who presented with primary amenorrhea, deepening of the voice, and clitoromegaly.


METHODS
Deoxyribonucleic acid was extracted from peripheral blood, and 8 exons of the androgen receptor gene and 5 exons of the steroid 5alpha-reductase type 2 gene (encoded by SRD5A2 gene) were amplified by polymerase chain reaction and subjected to sequence analyses.


METHODS
Genetic diagnosis of 5alpha-reductase deficiency.


RESULTS
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.


CONCLUSIONS
The molecular characterization of the mutation can be a relevant tool for a correct diagnosis of 5alpha-reductase deficiency.
Kim
Sung Hoon
SH
Department of Obstetrics and Gynecology, College of Medicine, University of Ulsan, Asan Medical Center, Seoul, Korea. kimsung@amc.seoul.kr
Kim
Kun Suk
KS
Kim
Gu Hwan
GH
Kang
Byung Moon
BM
Yoo
Han Wook
HW
D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase / Q000172:deficiency / Q000235:genetics*; D000293:Adolescent; D044466:Asian People / Q000235:genetics*; D003062:Codon; D012734:Disorders of Sex Development / Q000235:genetics* / Q000473:pathology; D005091:Exons; D005260:Female; D016368:Frameshift Mutation; D017353:Gene Deletion; D006720:Homozygote; D006801:Humans; D035781:Siblings; D013941:Thymine
D003062:Codon; D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase; C476567:steroid-5alpha-reductase type 2; D013941:Thymine