title: Association of SRD5A2 gene mutations with risk of hypospadias in the Iranian population.
abstract: BACKGROUND
  Hypospadias is one of the most common forms of congenital malformation of the male external genitalia worldwide. The ratio in the Iranian population is one in 250 live male births. The conversion of testosterone to dihydrotestosterone (DHT) in the presence of steroid 5α-reductase 2, which is encoded by SRD5A2 gene, plays an important role in the normal development of the male reproductive system.
  
  
  METHODS
  We examined whether SRD5A2 gene mutations (V89L and A49T polymorphisms) are associated with the risk of hypospadias in the Iranian population. We performed exons sequencing for SRD5A2 gene in 109 hypospadias patients.
  
  
  RESULTS
  We identified two new mutations in the subgroups of affected cases: including a substitution of the nucleotide T > A in the codon 73 [c.219T > A (p.Leu73_Ser74insHisPro)] and an insertion of an extra A nucleotide in the codon 77 [c.229insA* (p.Gly77*)]. Additionally, we performed PCR-RFLP for the two identified polymorphisms and revealed that V89L [OR = 5.8, 95% CI (3.8-8.8), p value < 0.001] and A49T [OR = 10.16, 95% CI (3.94-26.25), p value < 0.001] are significantly associated with hypospadias occurrence in patients. Our haplotype analysis further indicated that the Leu-Ala haplotype increases risk of hypospadias; conversely, the Val-Ala haplotype decreases the risk of hypospadias in the studied patients.
  
  
  CONCLUSIONS
  This study demonstrates that polymorphisms in the SRD5A2 gene could be considered as a risk factor for hypospadias disease emergence.
authors.affiliation: Department of Genetics, School of Medicine, Shahid Beheshti University of Medical Sciences, Koodakyar St., Daneshjoo Blvd., Evin, Chamran Highway, Tehran, Iran.
authors.forename: M
authors.initials: M
authors.lastname: Rahimi
authors.affiliation: Department of Epidemiology, Erasmus University Medical Center, Rotterdam, The Netherlands.|Department of Genetics, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: M
authors.initials: M
authors.lastname: Ghanbari
authors.affiliation: Department of Genetics, School of Medicine, Shahid Beheshti University of Medical Sciences, Koodakyar St., Daneshjoo Blvd., Evin, Chamran Highway, Tehran, Iran.
authors.forename: Z
authors.initials: Z
authors.lastname: Fazeli
authors.affiliation: Department of Pediatric Surgery, Mofid Children's Hospital, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: M
authors.initials: M
authors.lastname: Rouzrokh
authors.affiliation: School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: S
authors.initials: S
authors.lastname: Omrani
authors.affiliation: Department of Genetics, School of Medicine, Shahid Beheshti University of Medical Sciences, Koodakyar St., Daneshjoo Blvd., Evin, Chamran Highway, Tehran, Iran. r.mirfakhraie@sbmu.ac.ir.
authors.forename: R
authors.initials: R
authors.lastname: Mirfakhraie
authors.affiliation: Department of Genetics, School of Medicine, Shahid Beheshti University of Medical Sciences, Koodakyar St., Daneshjoo Blvd., Evin, Chamran Highway, Tehran, Iran. davood_omrani@sbmu.ac.ir.
authors.forename: M D
authors.initials: MD
authors.lastname: Omrani
mesh_terms: D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase / Q000235:genetics*; D016022:Case-Control Studies; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D007021:Hypospadias / Q000453:epidemiology* / Q000235:genetics*; D007492:Iran / Q000453:epidemiology; D008297:Male; D008565:Membrane Proteins / Q000235:genetics*; D009154:Mutation / Q000235:genetics*; D015995:Prevalence; D012307:Risk Factors; D013739:Testosterone / Q000097:blood
chemical_list: D008565:Membrane Proteins; D013739:Testosterone; D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase; C548468:SRD5A2 protein, human
keywords: Hypospadias; Iranian population; Mutation; SRD5A2 gene