Clinical characterization and analysis of the SRD5A2 gene in six Korean patients with 5alpha-reductase type 2 deficiency.
OBJECTIVE
The aim of this study was to perform a 5alpha-reductase type 2 gene (SRD5A2) analysis in 6 Korean patients with external genitalia ranging from predominantly female to male in whom 5alpha-reductase type 2 deficiency was suspected.


METHODS
Six patients from five unrelated families participated, and all of their parents were non-consanguineous. Three patients presented with ambiguous genitalia at birth, and 2 were referred owing to delayed puberty. The other patient was presented incidentally during an operation for inguinal hernia. Basal and post-human chorionic gonadotropin-stimulated serum testosterone and dihydrotestosterone levels were determined, but neither the levels nor ratio yielded enough information for differential diagnosis. Confirmative diagnosis was achieved by SRD5A2 gene analysis.


RESULTS
Four different pathologic mutations were identified. All have already been reported, and are located in exon 1 (p.Q6X), exon 4 (p.G203S and c.655delT), and exon 5 (p.R246Q). p.R246Q was the most frequently identified mutation in our study, and c.655delT has been detected only in Korean patients to date.


CONCLUSIONS
The molecular analysis is the most reliable method for a correct diagnosis of 5alpha-reductase type 2 deficiency. Identification of mutations also enables genetic counseling for families at risk.
Ko
Jung Min
JM
Department of Pediatric Endocrinology and Metabolism, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
Cheon
Chong-Kun
CK
Kim
Gu-Hwan
GH
Kim
Sung Hoon
SH
Kim
Kun Suk
KS
Yoo
Han-Wook
HW
D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase / Q000032:analysis / Q000172:deficiency* / Q000235:genetics*; D000293:Adolescent; D013734:Androgen-Insensitivity Syndrome / Q000150:complications / Q000235:genetics; D044466:Asian People / Q000235:genetics; D002675:Child, Preschool; D004252:DNA Mutational Analysis; D012734:Disorders of Sex Development / Q000150:complications / Q000235:genetics; D005260:Female; D006061:Gonadal Dysgenesis, 46,XY / Q000150:complications / Q000235:genetics; D006801:Humans; D007223:Infant; D007723:Korea; D008297:Male; D008565:Membrane Proteins / Q000032:analysis / Q000172:deficiency* / Q000235:genetics*; D011628:Puberty, Delayed / Q000150:complications / Q000235:genetics
D008565:Membrane Proteins; D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase; C548468:SRD5A2 protein, human