HOXA1 Mutations are Not Commonly Associated with Non-Syndromic Deafness.

Objective: Homozygous homeobox A1 (HOXA1) mutations cause a spectrum of abnormalities in humans including bilateral profound deafness. This study evaluates the possible role of HOXA1 mutations in familial, non-syndromic sensorineural deafness.

Methods: Forty-eight unrelated Middle Eastern families with either consanguinity or familial deafness were identified in a large deafness clinic, and the proband from each family was evaluated by chart review, audiogram, neuroimaging, and HOXA1 sequencing.

Results: All 48 probands had normal neuro-ophthalmologic and general medical examinations except for refractive errors. All had congenital non-syndromic sensorineural hearing loss that was symmetric bilaterally and profound (>90 dBHL) in 33 individuals and varied from 40 to 90 dBHL in the remainder. Thirty-nine of these individuals had neuroimaging studies, all documenting normal internal carotid arteries and normal 6th, 7th, and 8th cranial nerves bilaterally. Of these, 27 had normal internal ear structures with the remaining 12 having mild to modest developmental abnormalities of the cochlea, semicircular canals, and/or vestibular aqueduct. No patient had homozygous HOXA1 mutations.

Conclusions: None of these patients with non-syndromic deafness had HOXA1 mutations. None had major inner ear anomalies, obvious cerebrovascular defects, or recognized congenital heart disease. HOXA1 is likely not a common cause of non-syndromic deafness in this Middle Eastern population.