Re-analysis of the Hungarian amyotrophic lateral sclerosis population and evaluation of novel ALS genetic risk variants.

Amyotrophic lateral sclerosis (ALS) is a presently incurable neurodegenerative disease. Some genes have a causal relationship to ALS, others act as susceptibility and/or risk factors. We aimed to elucidate the role of 14 ALS-related genes in the Hungarian ALS population of 183 patients. Mutation screening of major ALS genes was performed. SMN1 and SMN2 genes were examined by multiplex ligation-dependent probe-amplification assay; intermediate repeat expansions in the ATXN1 and ATXN2 genes were analyzed by fragment analysis. Additional variants in putative ALS genes were screened from previously acquired next generation sequencing data. We confirmed the repeat expansion of the C9orf72, ATXN1 and ATXN2 genes as ALS risk factors in this Hungarian cohort. Additionally, we identified a pathogenic SOD1 mutation and suggested its founder effect. A likely pathogenic variant in the MFSD8 gene was detected, and variants of interest were uncovered in the ANXA11 and GLT8D1 genes. We provide valuable data as part of the growing body of work on population-specific aspects of the genetic background of ALS.