GENETICS OF AMYOTROPHIC LATERAL SCLEROSIS

Abstract

Approximately 10 to 15% of people with amyotrophic lateral sclerosis (ALS) have a family history of the disease. In 2/3 of them, but also in 10% of subjects without any family history of ALS, a pathogenic genetic variant can be identified. Many genes are involved, the four main ones being C9orf72 (which can also be responsible for dementia), SOD1, TARDBP and FUS. ALS of genetic origin is almost always inherited in an autosomal dominant pattern. The progress made in recent years in the knowledge of the genetic forms of ALS has led to a better understanding of the pathophysiology of the disease and has opened up new therapeutic avenues, some of which are already being explored. For all these reasons, it is now recommended that all patients with ALS, whether familial or not, undergo a genetic investigation, with analyses appropriate to their age and family history. When a pathogenic variant is found, it can then be sought in at-risk relatives who so desire. These tests must follow legally mandated procedures and can only be conducted in a specialized ALS center under the supervision of a geneticist after a thorough discussion of the personal and family implications of the result and written consent from the patient.