title: Molecular analysis of the 5 alpha-steroid reductase type 2 gene in a family with deficiency of the enzyme.
abstract: This report describes the identification of a point mutation in the 5 alpha-reductase type 2 (5 alpha-SR2) gene from a family in which both sibs (6 and 3 years old) have steroid 5 alpha-reductase 2 deficiency. The five exons of the gene were individually amplified by the polymerase chain reaction (PCR) and analysed for single-strand conformation polymorphisms (SSCP) to detect mutations. Direct sequencing of the mutant PCR products demonstrated a single C-->T mutation, within exon 4, changing codon 227 from CGA (Arg) to TGA (premature termination signal). Both patients were homozygous for the mutation, but their parents were heterozygous. These results suggest that the mutation at codon 227 impairs normal 5 alpha-SR2 function, thus leading to the phenotypical expression of this rare enzymatic defect.
authors.affiliation: Department of Reproductive Biology, Instituto Nacional de la Nutrición S.Z., México D.F., México.
authors.forename: F
authors.initials: F
authors.lastname: Vilchis
authors.forename: P
authors.initials: P
authors.lastname: Canto
authors.forename: B
authors.initials: B
authors.lastname: Chávez
authors.forename: A
authors.initials: A
authors.lastname: Ulloa-Aguirre
authors.forename: J P
authors.initials: JP
authors.lastname: Méndez
mesh_terms: D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase / Q000172:deficiency* / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D005091:Exons; D005190:Family; D005260:Female; D006801:Humans; D009154:Mutation; D016133:Polymerase Chain Reaction; D018807:Polymorphism, Single-Stranded Conformational
chemical_list: D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase