Abstract
Objective: Diabetic neuropathy, a long-term complication of type 2 diabetes (T2D), has a genetic inheritance component to its manifestation. We aimed at identifying whether the proteasome modulator 9 (PSMD9) gene responsible for linkage with T2D and maturity-onset diabetes of the young 3 in Italian families may play a role in the inheritance of diabetic neuropathy in T2D as well. Methods: We characterized the Italian families with T2D for presence and/or absence of diabetic neuropathy. The diabetic neuropathy is reported as unknown in all cases in which either the diagnosis was unclear or the data were not available for the subject studied. Thus, in our 200 Italian families, the data presence was less than 100%. We tested in the 200 Italians families for the presence of the linkage of the PSMD9 single nucleotide polymorphisms (SNPs) with diabetic neuropathy. The nonparametric as well as the parametric linkage analysis was performed by using the Merlin software; the LOD score and correspondent P value were calculated. For the significance and/or trends toward significance linkage score, 1000 replicates were performed to determine the empirical P value. Results: We report the linkage study of the PSMD9 SNPs [intervening sequence IVS3+nt460A/G, IVS3+nt437C/T and E197G] in Italian families with T2D neuropathy. Conclusion: In summary, the PSMD9 gene SNPs studied contribute to the genetic risk of diabetic neuropathy in our Italian data set, showing statistical significance for an additive model-based inheritance.