A research on TGFBI gene mutations in Chinese families with corneal dystrophies / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To identify what kind of TGFBI gene mutation happening to Chinese patients with corneal dystrophies.</p><p><b>METHODS</b>Three Chinese families with stromal corneal dystrophies and one Chinese family with Thiel-Behnke corneal dystrophies were studied, of whom three were Han race and another was Mongolia race in China. All members of families were examined clinically and their genomic DNAs were extracted from blood leukocytes. Thirteen exons in TGFBI gene were amplified by polymerase chain reaction (PCR) and directly sequenced for molecular analysis.</p><p><b>RESULTS</b>Mutations in TGFBI gene were detected from all the patients with corneal dystrophy, but not found in normal subjects of families. The mutation R555W was found and identified from the family with granular corneal dystrophy; R555Q from the family with Thiel-Behnke corneal dystrophy; and R124H from the other two families with Avellino corneal dystrophy.</p><p><b>CONCLUSION</b>The above study results show that the amino acids R124 and R555, if their genetic codes result from the mutations, play an important role in the pathogenesis of autosomal dominant corneal dystrophy of Chinese patients, and the molecular genetic analysis can improve the accuracy of diagnosing corneal dystrophy. In China, the mutation R555Q found in the family with Thiel-Behnke corneal dystrophy is reported for the first time.</p>

Autosomal dominant congenital nuclear cataract caused by a deletion mutation in the beta A1-crystallin gene / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To identify the genetic defect causing automosal dominant congenital cataracts (ADCC) with nuclear opacities in a Chinese pedigree.</p><p><b>METHODS</b>Linkage analysis was carried out with the short tandem repeat polymorphisms flanking the candidate genes. Mutation analysis of the candidate gene in the critical region was performed to detect the potential mutation.</p><p><b>RESULTS</b>The cataract locus in this pedigree was mapped to 17q11.1-12, an 11.78 cM interval between markers D17S933 and D17S 1288. By means of sequencing the candiate gene, betaA1-crystallin (CRYBA1), a deletion mutation DeltaG91 in exon 4 was detected. This change cosegregated with the patients in the family but was not found in 50 normal unrelated individuals.</p><p><b>CONCLUSION</b>It is a deletion mutation DeltaG91 of CRYBA1 gene that causes autosomal dominant congenital nuclear cataract. This is the first report of an autosomal dominant congenital nuclear cataract caused by the mutation in this gene.</p>