Clinical and immunohistochemical evidence for an X linked retinitis pigmentosa syndrome with recurrent infections and hearing loss in association with an RPGR mutation

Abstract

THE AUTHORS REPORT A FAMILY WITH X LINKED RECESsive retinitis pigmentosa (RP) associated with the unique phenotype of relapsing otitis media (ROM), recurrent upper respiratory tract infections (RUTI), and hearing loss, in which a G173R missense mutation in the RPBR gene was identified. In addition to classical RP in males and late onset mild patchy RP with a cone>rod pattern of dysfunction in carriers, audiometry showed mixed hearing loss in affected males with ROM and RUTI, and sensorineural loss in a female carrier who had also suffered from ROM. Using immunohistochemistry, the authors demonstrated specific RPGR expression in the epithelial lining of the sinuses, bronchi and cochlea. These findings provide additional evidence in favor of a broader phenotypic range in association with RPGR mutations than previously unsuspected and suggest an important role for RPBR in the respiratory tract and cochlea.—Hans E. Grossniklaus