title: [Analysis of CYP21A2 gene mutations among patients with classical steroid 21-hydroxylase deficiency].
abstract: OBJECTIVE
  To assess the frequencies of CYP21A2 gene mutations among patients from Fujian area with classical 21-hydroxylase deficiency.
  
  
  METHODS
  For 19 probands from different families affected with classical steroid 21-hydroxylase deficiency and 74 family members, mutations of the CYP21A2 gene were analyzed with combined nested polymerase chain reaction, Sanger sequencing and multiplex ligation-dependent probe amplification. Time resolved fluorescence immunoassay was performed to determine the level of 17-hydroxyprogesterone (17-OHP) in all family members. Clinical data and laboratory results of the probands and their family members were analyzed.
  
  
  RESULTS
  Eleven mutations were identified among the 38 alleles from the 19 probands. 92.1% (35/38) of the mutant CYP21A2 alleles were due to recombination between CYP21A2 and CYP21A1P. Gene conversion and deletions were identified in 84.2% (32/38) and 7.9% (3/38) of the alleles, respectively. IVS2-13A/C>G and chimeras were the most common mutations, which respectively accounted for 34.2% (13/38) and 18.4% (7/38) of all mutant alleles. Among these, IVS2+1G>A and Q318X+356W were first reported in China. 74.3% (55/74) of the family members were carriers of heterozygous mutations. However, no significant difference was found in the 17-OHP levels between carriers and non-carriers (P>0.05).
  
  
  CONCLUSIONS
  There seems to be a specific spectrum of CYP21A2 gene mutations in Fujian area, where IVS2-13A/C>G and chimeras are the most common mutations.
authors.affiliation: Center of Neonatal Screening, Fujian Provincial Maternity and Children's Hospital of Fujian Medical University, Fuzhou, Fujian 350001, China. hqchen_996@qq.com.
authors.forename: Yueqing
authors.initials: Y
authors.lastname: Su
authors.forename: Hanqiang
authors.initials: H
authors.lastname: Chen
authors.forename: Wenbin
authors.initials: W
authors.lastname: Zhu
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.forename: Jinfu
authors.initials: J
authors.lastname: Zhou
authors.forename: Yao
authors.initials: Y
authors.lastname: Chen
authors.forename: Hong
authors.initials: H
authors.lastname: Zhao
authors.forename: Yinglin
authors.initials: Y
authors.lastname: Zeng
authors.forename: Feng
authors.initials: F
authors.lastname: Lin
authors.forename: Honghua
authors.initials: H
authors.lastname: Zhang
authors.forename: Qingying
authors.initials: Q
authors.lastname: Lin
mesh_terms: D000312:Adrenal Hyperplasia, Congenital / Q000235:genetics*; D000483:Alleles; D005260:Female; D006801:Humans; D008297:Male; D009154:Mutation / Q000235:genetics*; D013255:Steroid 21-Hydroxylase / Q000235:genetics*
chemical_list: C531510:CYP21A2 protein, human; D013255:Steroid 21-Hydroxylase