Calpain-10 haplotype combination and association with gestational diabetes mellitus.

Gestational diabetes mellitus (GDM) is a frequent complication of pregnancy. Epidemiologic and pathophysiologic data suggest a close link of this disease to non-insulin-dependent diabetes mellitus. Within the calpain-10 gene various single-nucleotide polymorphisms have been identified that increased the risk for non-insulin-dependent diabetes mellitus. Therefore, we examined single-nucleotide exchanges of this gene in women with GDM. A total of 875 unselected women were prospectively screened for GDM. Eighty women of this population, 40 patients with an abnormal oral glucose tolerance test and 40 normal controls, were randomly selected. DNA samples isolated from sera of the control and study groups were analyzed with respect to single-nucleotide polymorphisms of the calpain-10 gene at positions 43, 19, and 63 using polymerase chain reaction amplification and restriction analysis. Women with GDM were more likely to be homozygous for the allele 1 of single-nucleotide polymorphism 63 (P =.02 by chi(2) test). With respect to single-nucleotide polymorphisms 19 and 43, no significant differences in allele distribution were detected between controls and women with GDM. When comparing the different haplotypes for calpain-10 (single-nucleotide polymorphisms 43, 19, and 63), all women with the haplotype combination 121/221 (n = 8) had gestational diabetes (P =.005 by Fisher exact test). Our results indicate that the haplotype 121/221 of the calpain-10 gene may be associated with disturbances of glucose metabolism during pregnancy. II-1