Common genetic link between metabolic syndrome components and senile cataract

Metabolic Syndrome Is Associated with Cataract in a Large Taiwanese Population Study

Cataract is the leading cause of blindness worldwide, and metabolic syndrome (MetS) is a known risk factor. In this study, we investigated the association between the risk of cataract with MetS and its components in a large-scale study. Data were derived from the Taiwan Biobank, and 121,380 individuals were included. The NCEP-ATP III criteria modified for use in an Asian population were used to define MetS and its components. The occurrence of cataract was identified through a standardized interview and self-reported questionnaire. Multivariable analysis showed that MetS (OR, 1.129; 95% CI, 1.0175−1.184; p < 0.001), low high-density lipoprotein (HDL)-cholesterol (OR, 1.057; 95% CI, 1.005−1.113; p = 0.032), and hyperglycemia (OR, 1.162; 95% CI, 1.108−1.218; p < 0.001) were significantly associated with cataract. Furthermore, a stepwise increase in the prevalence of cataract corresponding to the number of MetS components was found. The presence of three MetS components (vs. 0; OR, 1.103; 95% CI, 1.024−1.188; p = 0.010), four MetS components (vs. 0; OR, 1.137; 95% CI, 1.040−1.242; p = 0.005), and five MetS components (vs. 0; OR, 1.208; 95% CI, 1.059−1.378; p = 0.005) were significantly associated with cataract. In conclusion, significant associations were found between a high incidence of cataract with MetS and its components, including low HDL-cholesterolemia and hyperglycemia. Further, a stepwise increase in the prevalence of cataract corresponding to the number of MetS components was also found. The results of this study indicate that MetS may increase the development of cataract in Taiwan.

A large multiethnic GWAS meta-analysis of cataract identifies new risk loci and sex-specific effects

Cataract is the leading cause of blindness among the elderly worldwide and cataract surgery is one of the most common operations performed in the United States. As the genetic etiology of cataract formation remains unclear, we conducted a multiethnic genome-wide association meta-analysis, combining results from the GERA and UK Biobank cohorts, and tested for replication in the 23andMe research cohort. We report 54 genome-wide significant loci, 37 of which were novel. Sex-stratified analyses identified CASP7 as an additional novel locus specific to women. We show that genes within or near 80% of the cataract-associated loci are significantly expressed and/or enriched-expressed in the mouse lens across various spatiotemporal stages as per iSyTE analysis. Furthermore, iSyTE shows 32 candidate genes in the associated loci have altered gene expression in 9 different gene perturbation mouse models of lens defects/cataract, suggesting their relevance to lens biology. Our work provides further insight into the complex genetic architecture of cataract susceptibility.

Association between a Tetranucleotide Repeat Polymorphism of SPAG16 Gene and Cataract in Male Children

Purpose. Studies involving genotyping of STR markers at 2q34 have repeatedly found the region to host the disease haplotype for pediatric cataract. Present study investigated the association of D2S2944 marker, in sperm associated antigen 16 (SPAG16) gene and rs2289917 polymorphism, in γ-crystallin B gene, with childhood cataract. Methods. 97 pediatric cataract cases and 110 children with no ocular defects were examined for tetranucleotide repeat marker/SNP using PCR-SSLP/RFLP techniques. Polymorphisms were assessed for association using contingency tables and linkage disequilibrium among alleles of the markers was estimated. Energy-optimization program predicted the secondary structure models of repeats of D2S2944. Results. Seven alleles of D2S2944, with 9–15 “GATA” repeats, were observed. Frequency of the longer allele of D2S2944, ≥(GATA)₁₃ repeats, was 0.73 in cases and 0.56 in controls (P = 0.0123). Male children bearing ≥(GATA)₁₃ repeats showed >3-fold higher risk for cataract (CI_95% = 1.43–7.00, P = 0.0043, P_c = 0.0086) as compared to female children (OR = 1.19, CI_95% = 0.49–2.92, P = 0.70). Cases with haplotype—≥(GATA)₁₃ of D2S2944 and “C” allele rs2289917—have a higher risk for pediatric cataract (OR = 2.952, CI_95% = 1.595~5.463, P = 0.000453). >(GATA)₁₃ repeats formed energetically more favorable stem-loop structure. Conclusion. Intragenic microsatellite repeat expansion in SPAG16 gene increases predisposition to pediatric cataract by probably interfering posttranscriptional events and affecting the expression of adjacent lens transparency gene/s in a gender bias manner.