TRIPLET REPEAT POLYMORPHISM IN THE NOTCH4 GENE WITHIN THE HUMAN MAJORHISTOCOMPATIBILITY COMPLEX IN A HEALTHY POPULATION AND PATIENTS WITH A SALIVARY-GLAND TUMOR IN JAPAN

The NOTCH4 gene, the human counterpart of the mouse mammary tumor gene , int-3, has been recently localized near the boundary of the HLA clas s II and class III regions. This gene is one of candidates for develop ment of salivary gland tumor. Microsatellite polymorphism of (CTG)n re peat in the signal peptide domain of NOTCH4 was analyzed in Japanese i ncluding the patients with salivary gland tumor. Four alleles consisti ng of 6, 9, 10 and 11 repetitions of CTG (Leu) were observed and found to be in linkage disequilibria with HLA class I and class II alleles. No significant association of this microsatellite polymorphism with t he disease were observed in 26 samples of salivary gland tumor. In thi s neoplasia, neither large-scale deletion nor translocation was detect ed around the NOTCH4 gene using genomic Southern hybridization analysi s by the NOTCH4 cDNA as a probe.