OBJECTIVESTo confirm previous whole-genome scan results of mapping type 2 diabetes susceptibility genes in chromosome 1 in Northern Chinese Han population by conducting a new genome scan with both an enlarged number of type 2 diabetes families and a new set of microsatellite markers.

METHODSA genome scan method was applied. After multiplexed PCR, electrophoreses, genescan and genotyping analysis, size informations for all loci were obtained, and a further study was done using both parametric and non-parametric linkage analysis to calculate the P-values and Z-values of these loci.

RESULTSA total of 34 microsatellite markers distributed within 5 regions along chromosome 1 were surveyed, and 12,000 genotypes were screened. Evidence of linkage with diabetes was identified for 8 of the 34 loci (all the P-values of the 8 loci distributed in 3 regions were lower than 0.05, and the highest Z-value was 2.17). Interestingly, all the 5 markers at the P terminal 1p36.3-1p36.23 region, spanning a long range of 16.9 cM, suggested to be linked with the disease. The results of the other two regions were not consistent with the previous ones.

CONCLUSIONSThe study results have confirmed those gained in the previous genome-wide scan. The fact that all 5 loci at the P terminal region displayed linkage with diabetes suggests that more than 1 susceptibility gene may reside in this region.