Phenotypic characterization of retinitis pigmentosa associated with deafness.

Introduction

There are several syndromes that associate retinitis pigmentosa with deafness or hearing loss. The most frequent is Usher syndrome, a genetic disorder of autosomal recessive inheritance, which, in some cases, is accompanied by vestibular dysfunction. However, there are cases of families that despite having retinitis pigmentosa associated with deafness, cannot be classified as Usher or other syndromes due to additional findings.

Objective

To reassess the phenotypes of 103 families previously diagnosed as possible Usher syndrome and/or retinitis pigmentosa associated with deafness. Materials and methods: We conducted a descriptive and retrospective study by reviewing the medical records of 103 families with a probable clinical diagnosis of Usher syndrome and/or retinitis pigmentosa associated with deafness. Families whose clinical diagnosis did not correspond to the typical Usher syndrome were selected and evaluated ophthalmologically and audiologically. Demographic and clinical variables were analyzed.

Results

We selected and then reevaluated 14 families and 55 individuals as they did not correspond to a clinical diagnosis of Usher syndrome; 13.6% of the families initially considered to have typical Usher syndrome were later diagnosed with retinitis pigmentosa associated with deafness, another ocular symptom associated with hearing loss, retinitis pigmentosa, or isolated hearing loss in the same family.

Conclusions

Family studies are essential in cases where the symptoms do not match the typical Usher’ syndrome. In the cases of retinitis pigmentosa associated with deafness, a correct clinical diagnosis allows for focusing on the molecular analyses to establish a differential diagnosis. The need for nomenclature guidelines on these atypical findings is relevant to aid physicians and researchers in the best approach to these cases.