Acquired mutation of type II transforming growth factor-beta receptor gene in glomerulosclerosis

OBJECTIVE: To investigate the acquired mutation of type II transforming growth factor beta receptor TbetaR II gene plays a role in the process of glumerulosclerosis. METHODS: Biopsy specimens of 32 patients with primary focal segmental glomerulosclerosis (FSGS) were examined. Microdissection was used to isolate the morphologically normal glumeruli, segmental sclerotic glomeruli (SSG) global sclerotic glomeruli (GSG), and in the same specimen, representing the sequence of glomerulosclerosis. DNA was extracted by one-step method. The A10 microsatellite instability (709 approximately 718) in TbetaRII gene was detected by high-fidelity PCR and strand length polymorphism. Scanning technique was used to calculate the mutation rate of TBRII gene A10 sequence. RESULTS: A total of 192 sites of glomeruli from 32 patients were analyzed. The standard curve for mutant integrated pixel density (IPD) percentages (10% 32% 55% 75% 88%) versus DNA mutant ratios (17% 24% 53% 79% 95%) showed excellent linear correlation (r = 0.990 8). DNA from the glomeruli of NG, SSG, and GSG of all cases showed very low ratios of mutant allele (1 approximately 5%). CONCLUSION: Mutation of TbetaRII gene A10 microsatellite sequence can not been detected during the progress of glomerulosclerosis.