Genome-wide association study for refractive astigmatism reveals genetic co-determination with spherical equivalent refractive error: the CREAM consortium
Li Q., Wojciechowski R., Simpson CL., Hysi PG., Verhoeven VJM., Ikram MK., Höhn R., Vitart V., Hewitt AW., Oexle K., Mäkelä KM., MacGregor S., Pirastu M., Fan Q., Cheng C., St Pourcain B., McMahon G., Kemp JP., Northstone K., Rahi JS., Cumberland PM., Martin NG., Sanfilippo PG., Lu Y., Wang Y., Hayward C., Polašek O., Campbell H., Benčić G., Wright AF., Wedenoja J., Zeller T., Schillert A., Mirshahi A., Lackner KJ., Yip S., Yap M., Ried JS., Gieger C., Murgia F., Wilson JF., Fleck B., Yazar S., Vingerling JR., Hofman AF., Uitterlinden AG., Rivadeneira FF., Amin N., Karssen LC., Oostra BA., Zhou X., Teo Y., Tai ES., Vithana ENI., Barathi VA., Zheng Y., Siantar RG., Neelam K., Shin Y., Lam J., Yonova-Doing E., Venturini C., Hosseini SM., Wong H., Lehtimäki TJ., Kähönen M., Raitakari OT., Timpson NJ., Evans DMD., Khor CC., Aung T., Young TL., Mitchell PG., Klein BEK., Van Duijn CM., Meitinger TA., Jonas JB., Baird PN., Mackey DA., Wong TY., Saw S., Pärssinen O., Stambolian DE., Hammond CJ., Klaver CCW., Williams CJ., Paterson AD., Bailey-Wilson JE., Guggenheim JA.
© 2014 The Author(s) To identify genetic variants associated with refractive astigmatism in the general population, meta-analyses of genome-wide association studies were performed for: White Europeans aged at least 25 years (20 cohorts, N = 31,968); Asian subjects aged at least 25 years (7 cohorts, N = 9,295); White Europeans aged <25 years (4 cohorts, N = 5,640); and all independent individuals from the above three samples combined with a sample of Chinese subjects aged <25 years (N = 45,931). Participants were classified as cases with refractive astigmatism if the average cylinder power in their two eyes was at least 1.00 diopter and as controls otherwise. Genome-wide association analysis was carried out for each cohort separately using logistic regression. Meta-analysis was conducted using a fixed effects model. In the older European group the most strongly associated marker was downstream of the neurexin-1 (NRXN1) gene (rs1401327, P = 3.92E−8). No other region reached genome-wide significance, and association signals were lower for the younger European group and Asian group. In the meta-analysis of all cohorts, no marker reached genome-wide significance: The most strongly associated regions were, NRXN1 (rs1401327, P = 2.93E−07), TOX (rs7823467, P = 3.47E−07) and LINC00340 (rs12212674, P = 1.49E−06). For 34 markers identified in prior GWAS for spherical equivalent refractive error, the beta coefficients for genotype versus spherical equivalent, and genotype versus refractive astigmatism, were highly correlated (r = −0.59, P = 2.10E−04). This work revealed no consistent or strong genetic signals for refractive astigmatism; however, the TOX gene region previously identified in GWAS for spherical equivalent refractive error was the second most strongly associated region. Analysis of additional markers provided evidence supporting widespread genetic co-susceptibility for spherical and astigmatic refractive errors.