Abstract

Familial amyotrophic lateral sclerosis (FALS) cases linked to SOD1 mutations may sometimes present with unusual clinical features such as pure lower motor neuron involvement or sensory signs. The authors describe a FALS pedigree with the L144F SOD1 mutation in which all cases had respiratory involvement as a first symptom. Although atypical clinical features are not rare in ALS families, this is the first pedigree with respiratory-onset in three affected members. This unusual presentation led to delayed diagnosis in the proband and highlights the fact that respiratory-onset can occur in familial ALS cases carrying SOD1 mutation.