Article: article from journal or magazin.
Case report (case report): feedback on an observation with a short commentary.
Difficulties in diagnosis and treatment of 5alpha-reductase type 2 deficiency in a newborn with 46,XY DSD.
Hormone Research In Pædiatrics
Publication types: Case Reports ; Journal Article
BACKGROUND/AIMS: Steroid 5alpha-reductase deficiency (MIM*607306) caused by mutations in the SRD5A2 gene is characterized by a predominantly female phenotype at birth and significant virilization at puberty. The undermasculinization at birth results from low dihydrotestosterone (DHT) levels during fetal development as the type 2 isoenzyme activity is reduced. In puberty, when the type 1 isoenzyme activity increases, significant virilization occurs. Most 46,XY individuals with 5alpha-reductase 2 deficiency develop a male gender identity. CASE REPORT AND RESULTS: We present a case with a predominantly female phenotype and ambiguous external genitalia but a normal 46,XY karyotype. Plasma steroid analysis after beta-hCG stimulation at 8 days of age revealed a steroid profile estimated as normal with a testosterone (T)/DHT ratio of 9.5 initially misleading to the exclusion of 5alpha-reductase deficiency. However, mutation analysis of the SRD5A2 gene revealed a homozygote point mutation (Leu55Gln) confirming the diagnosis of 5alpha-reductase deficiency. A male phenotype was successfully achieved by hormone treatment with T and DHT after diagnosing 5alpha-reductase deficiency and a masculinization operation. As a side effect skeletal age accelerated temporarily. CONCLUSION: In individuals with predominantly female phenotype and suspected 5alpha-reductase deficiency, a T/DHT ratio during the neonatal period >8.5 might point to 5alpha-reductase deficiency. After confirmation of the diagnosis by molecular analysis of the SRD5A2 gene, a satisfactory change to a male phenotype can be achieved by hormone treatment preceding surgery.
3-Oxo-5-alpha-Steroid 4-Dehydrogenase/deficiency, 3-Oxo-5-alpha-Steroid 4-Dehydrogenase/genetics, Dihydrotestosterone/blood, Female, Gonadal Dysgenesis, 46,XY/enzymology, Gonadal Dysgenesis, 46,XY/genetics, Humans, Infant, Newborn, Male, Point Mutation, Testosterone/blood
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