Replication study identified EFEMP1 association with varicose vein predisposition among Indians

Abstract

BackgroundVaricose vein is a chronic condition that affects the lower extremities of the human body. Several factors have been implicated in the development of this disease, viz age, gender, weight, height and prolonged standing. Recently, genome-wide studies have identified genetic biomarkers that are associated with varicose veins in different ethnic groups. Such genetic studies are lacking in South Asians specifically in Indians where the prevalence of varicose veins is high, and it is important to replicate these variants in the stated population. The study aimed to replicate the association of genetic variants associated with varicose veins in this target population, which were found to be associated with the other ethnic groups.MethodologyThe studied cohort is of the Indian population comprising unrelated 104 varicose veins cases and 448 non-varicose vein controls. The samples were genotyped using the Illumina Global Screening Array. Using the genomic data from UK BioBank and 23andMe studied cohorts; eight genetic variants were selected to replicate in our dataset. The allelic association was performed to identify the effective allele and risk was estimated using odds ratio and p-value as level of significance. Multifactor Dimensionality Reduction was used to estimate the cumulative effect of variants in Indians.ResultVariant rs3791679 of EFEMP1 was found to be associated with varicose veins in Indians. After observing the association of the EFEMP1 with varicose veins, we further ensued to identify all genetic variants within EFEMP1 to uncover the additional variants associated with this trait. Interestingly, we identified six new variants of EFEMP1 gene that have shown association. Moreover, the cumulative effect of all associated variations was estimated and the risk was 2.7 times higher in cases than controls whereas independently their effect ranges from 0.37–1.58.ConclusionThis study identifies EFEMP1 as a potential gene related to the risk of varicose veins in Indians. It also highlights that evaluating the maximum number of variants of a gene rather than focusing solely on replicating single variations offers a more comprehensive and nuanced understanding of the genetic factors contributing to a complex trait like varicose veins.