Surakka I, Whitfield JB, Perola M, Visscher PM, Montgomery GW, Falchi M, Willemsen G, de Geus EJ, Magnusson PK, Christensen K, Sørensen TI, Pietiläinen KH, Rantanen T, Silander K, Widén E, Muilu J, Rahman I, Liljedahl U, Syvänen AC, Palotie A, Kaprio J, Kyvik KO, Pedersen NL, Boomsma DI, Spector T, Martin NG, Ripatti S, Peltonen L, GenomEUtwin Project
Twin Res Hum Genet 15 (6) 691-699 [2012-12-00; online 2012-10-04]
Genome-wide association analysis on monozygotic twin-pairs offers a route to discovery of gene environment interactions through testing for variability loci associated with sensitivity to individual environment/lifestyle. We present a genome-wide scan of loci associated with intra-pair differences in serum lipid and apolipoprotein levels. We report data for 1,720 monozygotic female twin-pairs from GenomEUtwin project with 2.5 million SNPs, imputed or genotyped, and measured serum lipid fractions for both twins. We found one locus associated with intra-pair differences in high-density lipoprotein cholesterol, rs2483058 in an intron of SRGAP2, where twins carrying the C allele are more sensitive to environmental factors(P=3.98 x 10-8). We followed up the association in further genotyped monozygotic twins (N= 1,261),which showed a moderate association for the variant (P= 0.200, same direction of an effect). In addition,we report a new association on the level of apolipoprotein A-ll (P= 4.03 x 1 o-8).