Brown-Vialetto-Van Laere syndrome; variability in age at onset and disease progression highlighting the phenotypic overlap with Fazio-Londe disease.
We report four siblings showing features of a pontobulbar palsy, a mixed spinal and upper motor neuropathy and variable deafness. The observation of affected males and females born to consanguineous first cousin parents suggests autosomal recessive inheritance. Two children presented in the first 16 months of life with stridor and died of respiratory failure by the age of 2 years. Hearing loss was not apparent in these infants. In contrast, 2 further siblings developed a bulbar palsy in their sixth year followed by the onset of deafness and features of an anterior horn neuropathy with corticospinal tract involvement. They exhibited a relatively slow but relentless decline over a period of several years. These cases highlight the phenotypic overlap of Brown-Vialetto-Van Laere syndrome with Fazio-Londe disease. Rather than representing two separate disorders, our findings suggest the possibility of a single disease entity which may usefully be considered a form of juvenile amyotrophic lateral sclerosis.