Background Congenital cataract is a highly heterogeneous disorder at both the genetic and phenotypic levels. This study was conducted to identify disease locus for autosomal dominant congenital cataracts in a four gen...Background Congenital cataract is a highly heterogeneous disorder at both the genetic and phenotypic levels. This study was conducted to identify disease locus for autosomal dominant congenital cataracts in a four generation Chinese family. Methods Family history and clinical data were recorded. All the members were genotyped with microsatellite markers which are close to the known genetic loci for autosomal congenital cataracts. Two-point Lod scores were obtained using the MLINK of the LINKAGE program package （vet 5.1）. Candidate genes were amplified by polymerase chain reaction （PCR） and direct cycle sequencing.Results The maximum Lod score of Zmax=2.11 was obtained with three microsatellite markers D22S258, D22S315, and D22S1163 at recombination fraction θ= 0. Haplotype analysis showed that the disease gene was localized to a 18.5 Mbp region on chromosome 22 flanked by markers D22S1174 and D22S270, spanning the β-crystallin gene cluster. A c.752T→C mutation in exon 6 of CRYBB1 gene, which resulted in a heterozygous S228P mutation in predicted protein, was found to cosegregate with cataract in the family.Conclusions This study identified a novel mutation in CRYBB1 gene in a Chinese family with autosomal dominant congenital cataract. These results provide strong evidence that CRYBB1 is a pathogenic gene for congenital cataract.展开更多
AIM：To summarize the phenotypes and identify the underlying genetic cause of the CRYBB1 and CRYBB2 gene responsible for congenital cataract in two Chinese families.METHODS：Detailed family histories and clinical data...AIM：To summarize the phenotypes and identify the underlying genetic cause of the CRYBB1 and CRYBB2 gene responsible for congenital cataract in two Chinese families.METHODS：Detailed family histories and clinical data were collected from patients during an ophthalmologic examination. Of 523 inheritable genetic vision systemrelated genes were captured and sequenced by targeted next-generation sequencing,and the results were confirmed by Sanger sequencing. The possible functional impacts of an amino acid substitution were performed with Poly Phen-2 and SIFT predictions.RESULTS：The patients in the two families were affected with congenital cataract. Sixty-five （FAMILY-1） and sixty two （FAMILY-2） single-nucleotide polymorphisms and indels were selected by recommended filtering criteria.Segregation was then analyzed by applying Sanger sequencing with the family members. A heterozygous CRYBB1 mutation in exon 4 （c.347T〉C, p.L116P） was identified in sixteen patients in FAMILY-1. A heterozygous CRYBB2 mutation in exon 5 （c.355G〉A, p.G119R） was identified in three patients in FAMILY-2. Each mutation cosegregated with the affected individuals and did not exist in unaffected family members and 200 unrelated normal controls.The mutation was predicted to be highly conservative and to be deleterious by both PolyPhen-2 and SIFT.CONCLUSION：TheCRYBB1 mutation（c.347T〉C）and CRYBB2 mutation （c.355G〉A） are novel in patients with congenital cataract. We summarize the variable phenotypes among the patients, which expanded the phenotypic spectrum of congenital cataract in a different ethnic background.展开更多
基金This study was supported by grants from National Natural Science Foundation(No.30471864)National Key Program(No.2003DEA3N026)of China.
文摘Background Congenital cataract is a highly heterogeneous disorder at both the genetic and phenotypic levels. This study was conducted to identify disease locus for autosomal dominant congenital cataracts in a four generation Chinese family. Methods Family history and clinical data were recorded. All the members were genotyped with microsatellite markers which are close to the known genetic loci for autosomal congenital cataracts. Two-point Lod scores were obtained using the MLINK of the LINKAGE program package （vet 5.1）. Candidate genes were amplified by polymerase chain reaction （PCR） and direct cycle sequencing.Results The maximum Lod score of Zmax=2.11 was obtained with three microsatellite markers D22S258, D22S315, and D22S1163 at recombination fraction θ= 0. Haplotype analysis showed that the disease gene was localized to a 18.5 Mbp region on chromosome 22 flanked by markers D22S1174 and D22S270, spanning the β-crystallin gene cluster. A c.752T→C mutation in exon 6 of CRYBB1 gene, which resulted in a heterozygous S228P mutation in predicted protein, was found to cosegregate with cataract in the family.Conclusions This study identified a novel mutation in CRYBB1 gene in a Chinese family with autosomal dominant congenital cataract. These results provide strong evidence that CRYBB1 is a pathogenic gene for congenital cataract.
基金Supported by China Postdoctoral Science Foundation Funded Project(No.2017M612211)Shandong Provincial Natural Science Foundation(No.ZR2018MH016)+3 种基金Qingdao Postdoctoral Application Research Project(No.40518060071)Medical Program of Shandong Province(No.2016WS0265)Qingdao Science and Technology Plan(No.16-6-2-14-nsh)Shandong Province Higher Educational Science and Technology Program(No.J17KA235)
文摘AIM：To summarize the phenotypes and identify the underlying genetic cause of the CRYBB1 and CRYBB2 gene responsible for congenital cataract in two Chinese families.METHODS：Detailed family histories and clinical data were collected from patients during an ophthalmologic examination. Of 523 inheritable genetic vision systemrelated genes were captured and sequenced by targeted next-generation sequencing,and the results were confirmed by Sanger sequencing. The possible functional impacts of an amino acid substitution were performed with Poly Phen-2 and SIFT predictions.RESULTS：The patients in the two families were affected with congenital cataract. Sixty-five （FAMILY-1） and sixty two （FAMILY-2） single-nucleotide polymorphisms and indels were selected by recommended filtering criteria.Segregation was then analyzed by applying Sanger sequencing with the family members. A heterozygous CRYBB1 mutation in exon 4 （c.347T〉C, p.L116P） was identified in sixteen patients in FAMILY-1. A heterozygous CRYBB2 mutation in exon 5 （c.355G〉A, p.G119R） was identified in three patients in FAMILY-2. Each mutation cosegregated with the affected individuals and did not exist in unaffected family members and 200 unrelated normal controls.The mutation was predicted to be highly conservative and to be deleterious by both PolyPhen-2 and SIFT.CONCLUSION：TheCRYBB1 mutation（c.347T〉C）and CRYBB2 mutation （c.355G〉A） are novel in patients with congenital cataract. We summarize the variable phenotypes among the patients, which expanded the phenotypic spectrum of congenital cataract in a different ethnic background.
