T2D variants were associated with PCOS phenotype parameters including those in THADA and WFS1 with testosterone levels, ENPP/PC1 with triglyceride levels, FTO with glucose levels and KCNJ11 with FSH levels.
A total of 1,578 non-diabetic individuals (534 men and 1,044 women, aged 40 +/- 13 years, BMI 28.9 +/- 8.2 kg/m(2) [mean +/- SD]) at increased risk of type 2 diabetes were genotyped for rs10010131 within the WFS1 gene.
All the risk alleles in the 11 examined type 2 diabetes risk variants showed an odds ratio (OR) greater than 1 for the GDM group compared with the control group ranging from 1.13 [95% confidence interval (CI) 0.88-1.46] to 1.44 (95% CI 1.19-1.74) except for the WFS1rs10010131 variant with OR 0.87 (95% CI 0.73-1.05).
Although the connection between loss of function mutations of the WFS1 gene and DIDMOAD-syndrome including diabetes mellitus underpins the significance of wolframin in the pathogenesis, exact role of WFS1 polymorphic variants in the development of type 1 and type 2 diabetes has not been discovered yet.
As common WFS1 gene variants have recently been shown to confer a risk of type 2 diabetes, our findings may be relevant to the gradual but progressive loss of beta cells in type 2 diabetes.
At six loci with genome-wide evidence for T2D association (AP3S2, KCNK16, NOTCH2, SCL30A8, VPS26A, and WFS1) predicted mRNA target sites for islet-expressed miRNAs overlapped potentially causal variants.
Examination of the publicly available Diabetes Genetics Initiative genome-wide association dataset revealed that rs10012946, which is in strong linkage disequilibrium with the three WFS1 SNPs (r(2)=0.88-1.0), was associated with type 2 diabetes (allelic odds ratio 0.85, 95% CI 0.75-0.97, p=0.026).
Genetic variants of WFS1, CDKAL1, CDKN2BAS, TCF7L2, HHEX, KCNQ1, TSPAN8/LGR5, FTO, and TCF2 were associated with the risk for T2D with MetS, as well as the risk for development of T2D with at least one of the MetS components (P < 0.05).
Identification of a missense variant in the WFS1 gene that causes a mild form of Wolfram syndrome and is associated with risk for type 2 diabetes in Ashkenazi Jewish individuals.
In addition, we found evidence for association of SNPs in the genes PPARG, IGF2BP2, HHEX, TCF7L2, and FTO with type 2 diabetes in the same directions as previously described (p<0.05), but not for WFS1, CDKN2A/B, KCNJ11, or EXT2.
Interaction between these SNPs were also strong using parametric or nonparametric methods: the unadjusted odds of being affected with T2D was 3 times greater in subjects with the HNF4A and WFS1 risk alleles than those without either (95% CI = [1.7-5.3]; P<or=0.0001).