The nuclear receptor hepatocyte nuclear factor 4alpha (HNF4alpha) contributes to the
regulation of a large fraction of liver and pancreatic islet transcriptomes.
To evaluate the influence of HNF4alpha polymorphisms across the entire locus on the
occurrence of type 2 diabetes (T2D) by means of a meta-analysis.
We evaluated haplotype block structure of HNF4alpha variants owing to linkage disequilibrium
(LD). From 1455 reports, we evaluated 21 observational studies.
Six haplotype blocks of LD were constructed with SNPs with r(2)>0.8; there were also
14 unlinked SNPs. Overall, we included 22,920 cases and 26.657 controls. Among 17
heterogeneous studies (21,881 cases and 24,915 controls), including 3 SNPs of P2 promoter
region in block 1, we observed a significant association with T2D in fixed (OR 0.94,
95%CI: 0.905-0.975, p=0.001) and random (OR 0.988, 95%CI: 0.880-0.948, p=0.000012)
model. Three homogeneous studies were evaluated in block 2 (2684 cases and 2059 controls),
and a significant association with T2D was also observed: OR: 1.121, 95%CI 1.013-1.241,
p=0.027. Three additional variants were associated with T2D: two intronic SNPs (rs4810424:
OR: 1.080, 95%CI: 1.010-1.154, p<0.03 and rs3212183: OR: 0.843, 95%CI: 0.774-0.918,
p<0.00009) and one missense variant (rs1800961: OR: 0.770, 95%CI: 0.595-0.995, p<0.05,
6562 cases and 6723 controls).
In addition to HNF4alpha variants in the promoter region, other SNPs may be involved
on the occurrence of T2D.