Brief Genetics Report Diabetes-Associated HLA-DQ Genes and Birth Weight

An association has recently been described between increased birth weight and increased risk of childhood-onset type 1 diabetes. Whether this relationship is explained by genes associated with both increased birth weight and increased risk of type 1 diabetes is unknown. In the present study, we tested the association between birth weight and HLA-DQ genotypes known to confer risk for type 1 diabetes among 969 nondiabetic children randomly selected from the Norwegian population. We found that HLA genotypes previously shown to confer risk for type 1 diabetes were associated with reduced birth weight (the mean difference in birth weight be-tween the DQB1*0602/DQB1*0602 and DQ8/DQ2 geno-types was 354 g [95 % CI 105–604]), which was opposite of that expected if HLA genes explained the birt