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.