Identification of novel mutations by targeted NGS in Moroccan families clinically diagnosed with a neuromuscular disorder

Abstract

Background and aims: The identification of underlying genes of genetic conditions has expanded greatly in the past decades, which has broadened the field of genes responsible for inherited neuromuscular diseases. We aimed to investigate mutations associated with neuromuscular disorders phenotypes in 2 Moroccan families.

Material and methods: Next-generation sequencing combined with Sanger sequencing could assist with understanding the hereditary variety and underlying disease mechanisms in these disorders.

Results: Two novel homozygous mutations were described in this study. The SIL1 mutation is the first identified in the Moroccan population, the mutation was identified as the main cause of Marinesco-Sjogren syndrome in one patient. While the second mutation identified in the fatty acid 2-hydroxylase gene (FA2H) was associated with the Spastic paraplegia 35 in another patient, both transmitted in an autosomal recessive pattern.

Discussion and conclusions: These conditions are extremely rare in the North African population and may be underdiagnosed due to overlapping clinical characteristics and heterogeneity of these diseases. We have reported in this study mutations associated with the diseases found in the patients. In addition, we have narrowed the phenotypic spectrum, as well as the diagnostic orientation of patients with neuromuscular disorders, who might have very similar symptoms to other disease groups.

Keywords: Hereditary spastic paraplegia type 35; Marinesco-Sjogren syndrome; Neuromuscular disorders; Next-generation sequencing; North Africa.