RESUMEN
OBJECTIVE@#To investigate the possible correlation between the microsatellite DNA instability(MSI) and loss of heterozygosity(LOH) on the short arm of chromosome 19(19p) and the clinical significance in patients with primary gastric carcinoma, and to explore the importance of MSI and LOH in primary gastric carcinoma.@*METHODS@#PCR-SSLP-silver stain method was used to detect 7 loci MSI and LOH in 79 primary gastric carcinomas and paired normal control tissues. The PCR products were separated by electrophoresis on polyacrylamide gel. Genescan and genotype softwares were used to analyze MSI and LOH.@*RESULTS@#LOH with at least one marker on 19p occurred in 31.18%(27/79)tumors. Among them, LOH at D19S591 and D19S565 was 60.32%(38/63)and 48.15%(26/54), respectively. The high incidence of LOH was related to depth of invasion and distant metastases of primary gastric carcinoma (P<0.05),and there was no significance between MSI and primary gastric carcinoma.@*CONCLUSION@#LOH is related to depth of invasion and distant metastases of primary gastric carcinoma.The high incidence of LOH suggests that there might be putative tumor gene in these LOH sites.