Familial Alström syndrome: a rare cause of bilateral progressive hearing loss.

INTRODUCTION Alström Syndrome is a rare disease caused by mutations in ALMS1 gene. It is characterized by a progressive degeneration of sensory functions, resulting in visual and audiological impairment, as well as metabolic disturbances such as childhood obesity, hyperinsulinemia, and diabetes mellitus type 2. OBJECTIVE To report and discuss the genetic and audiological findings in two siblings with Alström syndrome. METHODS This was a prospective, analytical and descriptive study, using questionnaires, serial audiograms, otoacoustic emissions, and auditory brainstem response analysis, as well as molecular genetic analysis. RESULTS Both patients presented childhood-onset bilateral sensorineural hearing loss, which progressed to moderate impairment in the first case and severe hearing loss in the second. Otoacoustic emissions were absent, and auditory brainstem responses were bilaterally normal in both cases. CONCLUSION In the present patients, Alström Syndrome began with a neurosensory hearing loss in early childhood that progressed to a profound loss in ten to twenty years. The auditory lesions were cochlear in origen according to the otoacoustic emissions and auditory brainstem responses.