title: A new compound heterozygous mutation (W17X, 436 + 5G --> T) in the cytochrome P450c17 gene causes 17 alpha-hydroxylase/17,20-lyase deficiency.
abstract: A genetic disorder in cytochrome P450c17 results in 17 alpha-hydroxylase/17,20-lyase deficiency. In the present study, a Japanese patient with 17 alpha-hydroxylase/17,20-lyase deficiency underwent molecular analysis. The patient presented with complete female genitalia with a 46,XY karyotype, absent pubertal development, and hypertension. the exons and exon-intron boundaries of P450c17 genetic region were amplified and sequenced. DNA sequencing revealed a compound heterozygous mutation. One allele showed a G to A transition corresponding to a premature termination codon at tryptophane in codon 17 (W17X). The other allele showed a G to T substitution at the fifth nucleotide from the splice donor site in intron 2 (436 + 5G --> T). W17X was found in one allele of the father, and 436 + 5G --> T was found in one allele of the mother. A previous report presented a patient with 17 alpha-hydroxylase/17,20-lyase deficiency who was homozygous for W17X. However, the present case is a novel 436 + 5G --> T mutation. Reverse transcription-PCR analysis using total ribonucleic acid isolated from the testes of the patient revealed that an intron 2 donor site mutation caused abnormal splicing, such that exon 2 was spliced with intron 2. Skipping the exon alters the translational reading frame of exon 3 and introduces a premature termination codon. In semiquantitative analysis, the majority of the transcript for 436 + 5G --> T skips exon 2. The present findings indicate that in this patient, 17 alpha-hydroxylase/17,20-lyase deficiency was caused by the compound heterozygous mutation of exon and splice site mutation in cytochrome P450c17 gene.
authors.affiliation: Department of Pediatrics, Gunma University School of Medicine, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Suzuki
authors.forename: T
authors.initials: T
authors.lastname: Nagashima
authors.forename: Y
authors.initials: Y
authors.lastname: Nomura
authors.forename: K
authors.initials: K
authors.lastname: Onigata
authors.forename: K
authors.initials: K
authors.lastname: Nagashima
authors.forename: A
authors.initials: A
authors.lastname: Morikawa
mesh_terms: D000293:Adolescent; D000312:Adrenal Hyperplasia, Congenital / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D005091:Exons; D005260:Female; D006580:Genetic Carrier Screening; D006801:Humans; D007438:Introns; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D013254:Steroid 17-alpha-Hydroxylase / Q000235:genetics*; D013256:Steroids / Q000097:blood / Q000652:urine
chemical_list: D013256:Steroids; D013254:Steroid 17-alpha-Hydroxylase