Introduction

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterised by progressive loss of motor neurons in the brain and spinal cord, leading to muscle weakness and death due to respiratory failure.1 Although most cases of ALS are sporadic, up to 10% of patients have a positive family history of ALS, usually associated with causative gene mutations.2 Latest evidence has shown that ALS is a complex multisystem disorder with extramotor involvement, namely, cognitive deficit and extrapyramidal dysfunction, expanding the clinical spectrum of the disease. Cognitive impairment is present in up to 50% of patients with ALS with different degrees of severity, and 15% of patients have a concomitant diagnosis of frontotemporal dementia (FTD).1 In fact, the clinical imaging and pathological and genetic overlap between ALS and FTD have led to the definition of an ALS/FTD continuum.1 Thus, one may speculate that a positive family history of neurodegenerative disorders (NDs) can be associated with ALS development. In this prospective case–control study, we aimed to describe the family aggregation of ND within the group of patients with ALS and to estimate the risk of ALS development in patients with a positive ND family history.