Molecular analysis of the 5α-steroid reductase type 2 gene in a family with deficiency of the enzyme

Vilchis, Felipe; Canto, Patricia; Chávez, Bertha; Ulloa‐Aguirre, Alfredo; Méndez, Juan Pablo

doi:10.1002/(sici)1096-8628(19970303)69:1<69::aid-ajmg13>3.0.co;2-m

Cited by 17 publications

(8 citation statements)

References 14 publications

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“…Consistent with this, experimental evidence has shown that all nonsense mutations in SRD5A2 lead to the synthesis of proteins with no detectable enzyme activity (Wilson et al 1996;Vilchis et al 1997;Sasaki et al 2003;Wang et al 2004). Furthermore, the in vitro experiments of site-directed mutagenesis confirmed that the P212X mutant enzyme is devoided of catalytic activity (Fig.…”

Section: Discussionsupporting

confidence: 59%

Novel compound heterozygous mutations in the SRD5A2 gene from 46,XY infants with ambiguous external genitalia

Vilchis

Valdez²,

Ramos

et al. 2008

J Hum Genet

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Dihydrotestosterone is crucial for normal development of external genitalia and prostate in the male embryo. Autosomal recessive mutations in the 5a-reductase type 2 (SRD5A2) gene disrupt the synthesis of dihydrotestosterone in the urogenital tract and give rise to genetic males with undervirilized external genitalia that may be femalelike or ambiguous. In this study, three unrelated 46,XY children (0.5, 3, and 8 years old) who presented severe undermasculinization at birth were examined for genetic abnormalities in the SRD5A2 gene. Coding sequence abnormalities were ascertained by exon-specific polymerase chain reaction (PCR), single-stranded conformational polymorphism (SSCP), and sequencing analysis. Functional properties of the mutant alleles were investigated by means of site-directed mutagenesis assays. DNA molecular studies showed that all three patients were compound heterozygotes for SRD5A2 mutations. Patient 1 had a point mutation 547G ? A in exon 3 (G183S) and a novel dinucleotidic mutation 634,635CC ? TG in exon 4 (P212X). This double change results in premature termination signal (TGA) at codon 212, which predicts the expression of a truncated 211-amino acid protein. Patient 2 was the carrier of mutations G115D in exon 3 and S210F in exon 4. Patient 3 had two substitution mutations in exon 1, including a novel G ? C transversion at nucleotide 169 (E57Q) and a G ? A transition at nucleotide 254 (G85D). In transitory transfection assays, the recombinant cDNAs harboring mutations E57Q and G85D showed residual 5a-reductase activity, whereas those with mutations G115D, S210F, and P212X were devoided of activity. In contrast, the G183S substitution affected the catalytic activity of the enzyme by decreasing its affinity for testosterone substrate. We describe six different mutations of the SRD5A2 gene detected in three children with genital ambiguity. These genotypes are consistent with the clinical phenotype of steroid 5a-reductase 2 deficiency. Our data suggest that the combined gene variants (E57Q/G85D, G115D/S210F, and G183S/P212X) result in subfunctional or nonfunctional enzymes, causing masculinization defects in these patients. This further underscores that exon 4 of SRD5A2 may be a site prone to inactivating mutations.

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Section: Discussionsupporting

confidence: 59%

Novel compound heterozygous mutations in the SRD5A2 gene from 46,XY infants with ambiguous external genitalia

Vilchis

Valdez²,

Ramos

et al. 2008

J Hum Genet

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“…Mutation of the SRD5A2 gene in codon 227 has been described in Creole Brazilians and Mexican Americans who presented with a premature termination codon (Thigpen et al, 1992; Vilchis et al, 1997). In those patients, the testes were extra‐abdominal, located in the inguinal canals, labia majora, or scrotum, but spermatogenesis was absent or was profoundly impaired in the 9 studied subjects.…”

Section: Discussionmentioning

confidence: 99%

“…AR gene exons 1–8 and SRD5A2 gene exons 1–5 were amplified by polymerase chain reaction (PCR). The primers used in the amplification of the SRD5A2 gene have been described by Vilchis et al (1997). PCR amplification of exon 1 was carried out in a volume of 12.5 μL containing 50 ng of genomic DNA, 0.5 mM of each primer, 0.375 U of FailSafe PCR Enzyme Mix, and Premix D (EPICENTRE, Madison, Wis).…”

Section: Methodsmentioning

confidence: 99%

“…Later, a cluster of male pseudohermaphrodite (MPH) patients were described in whom deficient virilization was attributable to an almost complete lack of this enzyme activity (Imperato‐McGinley et al, 1974; Imperato‐McGinley and Peterson, 1976). A number of deletions and point mutations in the 5‐α‐reductase type 2 gene ( SRD5A2 ) gene that encodes the 5‐α‐reductase type 2 enzyme (Labrie et al, 1992) have been shown to occur in patients with various clinical and biochemical phenotypes (Thigpen et al, 1992; Wilson et al, 1993; Boudon et al, 1995a,b; Cai et al, 1996; Hochberg et al, 1996; Vilchis et al, 1997, 2000; Can et al, 1998; Nordenskjold and Ivarsson, 1998; Nordenskjold et al, 1998; Chavez et al, 2000; Hiort et al, 2002; Hafez et al, 2003; Mazen et al, 2003a,b). The phenotypes of newborn MPH patients with partial androgen insensitivity (PAIS), 5‐α‐reductase enzyme deficiency, or 17‐β‐hydroxysteroid dehydrogenase enzyme deficiency may be indistinguishable.…”

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confidence: 99%

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Compound Heterozygous Mutations in the SRD5A2 Gene Exon 4 in a Male Pseudohermaphrodite Patient of Chinese Origin

Fernández‐Cancio¹,

Nistal

Gracía

et al. 2004

Journal of Andrology

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The goal of this study was to perform 5-alpha-reductase type 2 gene (SRD5A2) analysis in a male pseudohermaphrodite (MPH) patient with normal testosterone (T) production and normal androgen receptor (AR) gene coding sequences. A patient of Chinese origin with ambiguous genitalia at 14 months, a 46,XY karyotype, and normal T secretion under human chorionic gonadotropin (hCG) stimulation underwent a gonadectomy at 20 months. Exons 1-8 of the AR gene and exons 1-5 of the SRD5A2 gene were sequenced from peripheral blood DNA. AR gene coding sequences were normal. SRD5A2 gene analysis revealed 2 consecutive mutations in exon 4, each located in a different allele: 1) a T nucleotide deletion, which predicts a frameshift mutation from codon 219, and 2) a missense mutation at codon 227, where the substitution of guanine (CGA) by adenine (CAA) predicts a glutamine replacement of arginine (R227Q). Testes located in the inguinal canal showed a normal morphology for age. The patient was a compound heterozygote for SRD5A2 mutations, carrying 2 mutations in exon 4. The patient showed an R227Q mutation that has been described in an Asian population and MPH patients, along with a novel frameshift mutation, Tdel219. Testis morphology showed that, during early infancy, the 5-alpha-reductase enzyme deficiency may not have affected interstitial or tubular development.

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“…In addition, we selected 16 boys with severe hypospadias and cryptorchidism to sequence the SF-1 gene (2-7 exons). The primers used for the amplification of exons of the SRD5A2, AR and SF-1 genes have been described previously (7)(8)(9). PCR was performed in a final volume of 50 μL that contained 200 ng genomic DNA, 20 pmol of each primer, 200 μM dNTPs, 1.5 mM MgCl 2 and 2.5 U Taq polymerase (Sangon, Shanghai, China).…”

Section: Dna Sequence Analysismentioning

confidence: 99%

Mutation analysis of the SRD5A2, AR and SF-1 genes in 52 Chinese boys with hypospadias

Wang

Dong

Wang

et al. 2013

Journal of Pediatric Endocrinology and Metabolism

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Molecular analysis of the 5α-steroid reductase type 2 gene in a family with deficiency of the enzyme

Cited by 17 publications

References 14 publications

Novel compound heterozygous mutations in the SRD5A2 gene from 46,XY infants with ambiguous external genitalia

Novel compound heterozygous mutations in the SRD5A2 gene from 46,XY infants with ambiguous external genitalia

Compound Heterozygous Mutations in the SRD5A2 Gene Exon 4 in a Male Pseudohermaphrodite Patient of Chinese Origin

Mutation analysis of the SRD5A2, AR and SF-1 genes in 52 Chinese boys with hypospadias

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