title: A novel P20R mutation in the alpha-B crystallin gene causes autosomal dominant congenital posterior polar cataracts in a Chinese family.
abstract: BACKGROUND
  To identify the genetic defects and investigate the possible mechanism of cataract genesis in a five-generation family with autosomal dominant congenital posterior polar cataracts.
  
  
  METHODS
  Clinical data were collected, and the lens phenotypes of the affected members in this family were recorded by slit lamp photography. Genomic DNA was isolated from peripheral blood using QIAamp DNA Blood Mini Kits. Twenty-three mutational hot spots associated with autosomal dominant congenital posterior polar cataracts were screened by PCR-based DNA sequencing. Properties and structural models of wild-type and mutant alpha-B (αB)-crystallin (CRYAB) were generated and analyzed using SWISS-MODEL.
  
  
  RESULTS
  All affected individuals in this family started to exhibit poor vision at the age of 8-10 years. The lens opacity consisted of a single, well-defined plaque, 0.5-3 mm in diameter, which was confined to the posterior pole of the lens. DNA sequencing analysis of the affected members showed a novel, heterozygous missense mutation c.59C > G (P20R) in exon 1 of the CRYAB gene. This mutation was not found in 10 unaffected family members, or in 200 unaffected and unrelated individuals, thereby excluding the possibility that it is a rare polymorphism. Data generated using the ProtScale and PyMOL programs revealed that the mutation altered the stability and solubility of the αB-crystallin protein.
  
  
  CONCLUSIONS
  This study reported a novel c.59C > G (P20R) missense mutation in CRYAB in a five-generation Chinese family with posterior polar cataract.
authors.forename: Xin-Yi
authors.initials: XY
authors.lastname: Xia
authors.forename: Qiu-Yue
authors.initials: QY
authors.lastname: Wu
authors.forename: Li-Mei
authors.initials: LM
authors.lastname: An
authors.forename: Wei-Wei
authors.initials: WW
authors.lastname: Li
authors.forename: Na
authors.initials: N
authors.lastname: Li
authors.forename: Tian-Fu
authors.initials: TF
authors.lastname: Li
authors.forename: Cui
authors.initials: C
authors.lastname: Zhang
authors.forename: Ying-Xia
authors.initials: YX
authors.lastname: Cui
authors.affiliation: Institute of Laboratory Medicine, Jinling Hospital, Nanjing University School of Medicine, 305 East Zhongshan Road, Nanjing 210002, People's Republic of China. lixiaojun1962@gmail.com.
authors.forename: Xiao-Jun
authors.initials: XJ
authors.lastname: Li
authors.forename: Chun-Yan
authors.initials: CY
authors.lastname: Xue
mesh_terms: D002386:Cataract / Q000151:congenital / Q000235:genetics* / Q000378:metabolism; D002648:Child; D002681:China; D004247:DNA / Q000235:genetics*; D004252:DNA Mutational Analysis; D005260:Female; D006801:Humans; D007908:Lens, Crystalline / Q000378:metabolism*; D008297:Male; D009154:Mutation; D010375:Pedigree; D038203:alpha-Crystallin B Chain / Q000235:genetics* / Q000378:metabolism
chemical_list: D038203:alpha-Crystallin B Chain; D004247:DNA