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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: OBJECTIVE, METHODS, RESULTS. Meshes: Amino Acid Sequence, Asian Continental Ancestry Group, Asparagine, Aspartic Acid, Base Sequence, Cataract, Chromosomes, Human, Pair 13, Connexins, Female, Genes, Dominant, Genetic Linkage, Genotype, Haplotypes, Humans, Lens, Crystalline, Lod Score, Male, Microsatellite Repeats, Molecular Sequence Data, Mutation, Missense, Pedigree.
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Is a novel mutation in the GJA3 ( connexin46 ) gene associated with autosomal dominant congenital nuclear cataract in a Chinese family? Context: Congenital cataract is both a clinically and genetically heterogeneous lens disorder. The purpose of this study is to map and identify the mutation in an autosomal dominant congenital nuclear cataract in a Chinese family. Patients were given physical examinations and their blood samples were collected for DNA extraction. Genotyping was performed by microsatellite markers and logarithm of odds (LOD) scores were calculated using the LINKAGE programs. Mutation detection was performed by direct sequencing. Linkage to the gap-junction protein α3 (GJA3) locus was verified. Sequencing of GJA3 revealed a G>A transition at nucleotide position c.139, which causes an Asn substitution for the conservative Asp at codon 47 (P.D47N).This mutation is identified in all affected individuals but is not found in 100 control chromosomes.
assistant
Our results identify that the mutation (D47N) in GJA3 is responsible for this Chinese pedigree. It is further identified that GJA3 is responsible for congenital cataract. In our study, the novel mutation broadens the spectrum of GJA3 mutations. Final Decision: yes