DNA from non-diabetic Caucasians (n = 16), Blacks (n = 22), Hispanics (n = 13) and Japanese (n = 21), as well as DNA from 34 Caucasian, 19 Black, 19 Hispanic and 20 Japanese non-insulin-dependent diabetes mellitus (NIDDM) patients were examined for restriction fragment length polymorphism (RFLP) after digestion with enzymes BglII and XbaI, and hybridization with the glucose transporter probe, hGT2-2.