A recent report has shown an association between a specific Xba1 restriction fragment of the human HepG2-Erythrocyte glucose transporter gene and Type 2 (non-insulin dependent) diabetes. To further examine the significance of this finding we have studied Type 2 diabetic pedigrees for linkage between the Xba1 alleles of this glucose transporter gene and diabetes. One large pedigree, in which the diabetic phenotype was associated with obesity and insulin resistance, was informative. In this family the disease did not co-segregate with the glucose transporter locus. Formal linkage analysis was performed assuming autosomal dominant inheritance with age-dependent penetrance. At putative gene frequencies of 0.01 and 0.001 the logarithm of the odds for linkage versus non-linkage at a recombination fraction of 0.001 was -1.84 and -3.32 respectively (a value of less than -2 indicates definite non-linkage). Genetic variations in the HepG2-Erythrocyte glucose transporter gene are unlikely to be responsible for the development of diabetes in this pedigree.