MFN2 and frontotemporal dementia: Interestingly, a few cases of occurrence of amyotrophic lateral sclerosis/frontotemporal dementia with MFN2 mutations have been reported in the literature.8,9 More recently, Russel et al. 10 reported six rare MFN2 variants, which were classified as deleterious according to the VAAST (Variant Annotation, Analysis and Search Tool) and Phevor (Phenotype Driven Variant Ontological Re-ranking) software, within a cohort of 140 amyotrophic lateral sclerosis patients, and other 15 variants in the publicly available database ALSdb, composed of ∼2800 amyotrophic lateral sclerosis patients.