title: Novel beta-crystallin gene mutations in Chinese families with nuclear cataracts.
abstract: OBJECTIVE
  To investigate the molecular genetic background in families with nuclear congenital cataract.
  
  
  METHODS
  Family history and clinical data were recorded. Ten candidate genes were screened for causative mutations. Direct sequencing was performed to analyze the cosegregation of the genotype with the disease phenotype. Effects of amino acid changes on the structure and function of protein were predicted by bioinformatics analysis.
  
  
  RESULTS
  Analyses of 20 Chinese families with hereditary nuclear congenital cataract revealed 3 novel mutations. Two of these mutations (V146M and I21N) affected βB2-crystallin (CRYBB2). One mutation (R233H) was detected in βB1-crystallin (CRYBB1). These mutations cosegregated with all affected individuals and were not observed in unaffected family members or the 150 healthy unrelated individuals.
  
  
  CONCLUSIONS
  The CRYBB2 gene was shown to be another causative gene associated with congenital cataract and microcornea. Three novel mutations in β-crystallin genes (CRYB) were detected in Chinese families with nuclear autosomal dominant congenital cataracts, which underscores the genetic heterogeneity of this condition.
  
  
  CONCLUSIONS
  Studying the genetics of nuclear cataracts is helpful for better understanding the pathophysiologic mechanisms that underlie this phenotype and for better disease management. This study helps expand the genotype of nuclear cataract and microcornea.
authors.affiliation: Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Sciences Key Lab, Beijing, China.
authors.forename: Kai Jie
authors.initials: KJ
authors.lastname: Wang
authors.forename: Bin Bin
authors.initials: BB
authors.lastname: Wang
authors.forename: Fengju
authors.initials: F
authors.lastname: Zhang
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Zhao
authors.forename: Xu
authors.initials: X
authors.lastname: Ma
authors.forename: Si Quan
authors.initials: SQ
authors.lastname: Zhu
mesh_terms: D000595:Amino Acid Sequence; D044466:Asian People / Q000235:genetics; D001483:Base Sequence; D002386:Cataract / Q000175:diagnosis / Q000235:genetics*; D002675:Child, Preschool; D002681:China / Q000208:ethnology; D017630:Connexins / Q000235:genetics; D003315:Cornea / Q000002:abnormalities; D004252:DNA Mutational Analysis; D017931:DNA Primers / Q000737:chemistry; D005124:Eye Abnormalities / Q000235:genetics; D005260:Female; D005838:Genotype; D006801:Humans; D007907:Lens Nucleus, Crystalline / Q000473:pathology; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation; D010375:Pedigree; D016133:Polymerase Chain Reaction; D038206:beta-Crystallin B Chain / Q000235:genetics*
chemical_list: C105601:CRYBB1 protein, human; D017630:Connexins; D017931:DNA Primers; D038206:beta-Crystallin B Chain; C113634:beta-crystallin B2