Computational identification of personal genetic variants in an identical twin sisters' family

Abstract

Nowadays, scientists still have a limited understanding of how much genetic variation exists between identical twins. This study aims to analyse genotypic differences between identical twins and annotate the functional variants. We employed the 23andMe genotyping service to compare the genomes of twin sisters and their family members. With 162,400 SNPs genotyped at the autosomes, we found that there were 64,083 (10.26%) differences between one of the twins and their sibling brothers, while only 2530 differences (0.41%) existed between twin sisters. In total, among the 1974 nonsynonymous variants genotyped, excluding 'no calls,' only 17 shared nonsynonymous pathogenic variants between twin sisters were identified. The 16 pathogenic variants harboured genes are enriched with six significant terms associated with liver function and metabolic pathways. Our research could provide insight for physicians conducting studies related to genetic variations and personalised treatment of genetic disorders of identical twins.