Variations in the vitamin D-binding protein (Gc locus) are associated with oral glucose tolerance in nondiabetic Pima Indians.
Electrophoretic variants of the vitamin D-binding protein (DBP) have been associated with type 2 diabetes as well as with metabolic characteristics that predispose to type 2 diabetes in several populations. The Gc gene that encodes DBP maps to chromosome 4q12, a region that has recently been found to be potentially linked to plasma glucose and insulin concentrations in Pima Indians. Therefore, the gene that encodes DBP was analyzed as a candidate gene for our linkage findings in the Pima Indians. Sequence analysis of the coding exons identified two previously described missense polymorphisms at codons 416 and 420, which are the genetic basis for the three common electrophoretic variants of DBP (Gc1f, Gc1s, and Gc2). These variants in DBP were associated with differences in oral glucose tolerance in nondiabetic Pima Indians.
Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Arizona 85016, USA. lbaier@phx.niddk.nih.gov
L J
LJ
Baier
A M
AM
Dobberfuhl
R E
RE
Pratley
R L
RL
Hanson
C
C
Bogardus
D000328:Adult; D000483:Alleles; D001786:Blood Glucose / Q000378:metabolism; D002894:Chromosomes, Human, Pair 4; D003924:Diabetes Mellitus, Type 2 / Q000235:genetics; D005260:Female; D005787:Gene Frequency; D014644:Genetic Variation; D005951:Glucose Tolerance Test; D006801:Humans; D007198:Indians, North American / Q000235:genetics*; D007328:Insulin / Q000097:blood; D008297:Male; D011110:Polymorphism, Genetic; D011236:Prediabetic State / Q000235:genetics*; D014809:Vitamin D-Binding Protein / Q000235:genetics*
D001786:Blood Glucose; D007328:Insulin; D014809:Vitamin D-Binding Protein