YVDD Mutation of Hepatitis B Virus, a Dominant Lamivudine-Resistant Type in Guangzhou, South China

The epidemiological effects of native and mutated YMDD motif in the HBV genome under the selective pressure of lamivudine were investigated. YMDD wild and mutation motif in HBV genome were detected by flow through reverse dot blots （PT-RDB） with KaiPuTM DNA HybriMax Rapid Hybridization Machine based on the principle of ＂Flow-through hybridization＂ and by the traditional Reverse Dot Blot assay. Sera from 1 021 suspected lamivudine-resistant chronic HBV carriers after more than 8 months of lamivudine therapy and the corresponding archived sera were collected and assayed. We found 35.94% were single type infections with 8.03% YMDD, 7.93% YIDD and 19.98% YVDD. It was also found that 64.06% were mixed infections including 1.96% YMDD and YIDD, 51.62% YMDD and YVDD, 1.96% YIDD and YVDD, 8.52% YMDD, YIDD and YVDD. The levels of infections containing YVDD motif reached 82.08%. The pretreatment infectious status were： YMDD single infection was 36.93%; YIDD single infection was 6.07%; YVDD single infection was 17.04%; YMDD and YIDD mixed infection was 0.97%; YMDD and YVDD mixed infection was 33.99%; YIDD and YVDD mixed infection was 0.98%; YMDD, YIDD and YVDD mixed infection was 4.02%. Infections containing YVDD motif were only 56.03%. The 34.32% mutation rate of YMDD motif to YVDD was significantly higher than the 10.97% of YMDD to YIDD （U=10.98, P〈0.05）, as estimated by Mann-Whitney U-test for non-parametric data. HBV containing YVDD motif might have an evolutionary ascendancy and become the dominant type under the selective pressure of lamivudine.

Novel OCRL1 gene mutations in six Chinese families with Lowe syndrome

Background:Lowe syndrome,an X-linked,inheritable disease with clinical symptoms of congenital cataracts,incomplete Fanconi syndrome,and mental retardation,has an approximate incidence of 1 in 500000.Nearly 200 OCRL mutations related to Lowe syndrome have been found worldwide,with only ten mutations among the Chinese population.Since more mutations may exist in Chinese patients,we sequenced and analyzed the OCRL genes of six children with Lowe syndrome in a medical center in China.Methods:Peripheral blood was collected from six children with Lowe syndrome and their relatives,and ten healthy adults.Genomic DNA was extracted from the blood and applied to amplify the twenty-four exons and flanking introns of the OCRL gene.The mutations were identified by sequencing.Results:Five mutations(c.1528C>T,c.2187insG,c.1366C>T,c.1499G>A,and c.2581G>A)of the OCRL gene were found in five families;c.2187insG and c.1366C>T were novel mutations.None of the five mutations were detected in 20 normal chromosomes.No mutation was found in the sixth family.Conclusion:Two novel mutations of the OCRL gene,c.2187insG and c.1366C>T,were found in Chinese patients with Lowe syndrome,which will provide new clues for the etiology of Lowe syndrome and could be beneficial to genetic diagnosis of the condition.