Genetic analysis of Indian sporadic young onset patient with Amyotrophic Lateral Sclerosis

Abstract

BackgroundAmyotrophic lateral sclerosis (ALS) is an old onset devastating neurodegenerative disorder. Young-onset ALS cases especially sporadic ones who are between 25 and 45 years are rarely affected by the disease. Despite the identification of numerous candidate genes associated with ALS, the aetiology of the disease remains elusive due to extreme genetic and phenotypic variability. The advent of affordable whole exome sequencing has opened new avenues for unraveling the disease’s pathophysiology better.Methods and ResultsOur aim was to determine the genetic basis of an Indian-origin, young onset sporadic ALS patient with very rapid deterioration of the disease course without any cognitive decline who was screened for mutations in major ALS candidate genes by Whole exome sequencing. Variants detected were reconfirmed by Sanger Sequencing. The clinicopathological features were investigated and two heterozygous missense variants harboring each inANXA11,in one of the four conserved C terminal domains (R452W) and another in theSIGMAR1(R208W) were thus identified respectively. Both of these variants were predicted to be damaging by pathogenicity prediction tools and variousIn silicomethods.ConclusionsOur study revealed two potentially pathogenic variants in two ALS candidate genes. The genetic makeup of ALS patients from India has been the subject of a few prior studies, but none of them examinedANXA11andSIGMAR1genes so far. These results establish the framework for additional research into the pathogenic processes behind these variations that result in sporadic ALS disease and further our understanding of the genetic makeup of Indian ALS patients.