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 CY., St Pourcain B., McMahon G., Kemp JP., Northstone K., Rahi JS., Cumberland PM., Martin NG., Sanfilippo PG., Lu Y., Wang YX., Hayward C., Polašek O., Campbell H., Bencic G., Wright AF., Wedenoja J., Zeller T., Schillert A., Mirshahi A., Lackner K., Yip SP., Yap MKH., Ried JS., Gieger C., Murgia F., Wilson JF., Fleck B., Yazar S., Vingerling JR., Hofman A., Uitterlinden A., Rivadeneira F., Amin N., Karssen L., Oostra BA., Zhou X., Teo YY., Tai ES., Vithana E., Barathi V., Zheng Y., Siantar RG., Neelam K., Shin Y., Lam J., Yonova-Doing E., Venturini C., Hosseini SM., Wong HS., Lehtimäki T., Kähönen M., Raitakari O., Timpson NJ., Evans DM., Khor CC., Aung T., Young TL., Mitchell P., Klein B., van Duijn CM., Meitinger T., Jonas JB., Baird PN., Mackey DA., Wong TY., Saw SM., Pärssinen O., Stambolian D., Hammond CJ., Klaver CCW., Williams C., 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.