Supplementary Material for: Genome-Wide Association Studies for Albuminuria of non-Diabetic Taiwanese Population

Background Chronic renal disease (CKD), defined by reduced estimated glomerular filtration rate (eGFR) and albuminuria, imposes huge health burden worldwide. Ethnicity-specific associations were frequently observed in genome-wide association studies (GWAS). In this research, we conducted GWAS of albuminuria in the non-diabetic population of Taiwan.
Subjects and Methods Non-diabetic individuals aged 30 to 70 years and without cancer history were enrolled from the Taiwan Biobank. A total of 6,768 subjects received spot urine examination. After quality control with PLINK and imputation with SHAPEIT and IMPUTE2, a total of 3,638,350 single nucleotide polymorphisms (SNPs) remained for testing. SNPs with minor allele frequency low than 0.1% were excluded. We applied linear regression for analyzing associations between SNPs and log UACR.
Results We identified six loci in or near the FCRL3 (P = 2.56 × 10−6), TMEM161(P = 4.43 × 10−6), EFCAB1 (P = 2.03 × 10−6), ELMOD1 (P = 2.97 × 10−6), RYR3 (P = 1.34 × 10−6), and PIEZO2 (P = 2.19 × 10−7) as candidate. Genetic variants in the FCRL3 gene that encodes a secretory IgA receptor were found to be associated with IgA nephropathy, which might manifest proteinuria. The PIEZO2 gene encodes a sensor for mechanical forces in mesangial cells and renin-producing cells.
Conclusion We identified five new loci and one known suggestive loci for albuminuria in the non-diabetic Taiwanese population.