Caracterización fenotípica de la retinitis pigmentaria asociada a sordera / Phenotypic characterization of retinitis pigmentosa associated with deafness

RESUMEN

Introducción. El síndrome de Usher es una alteración genética caracterizada por la asociación de retinitis pigmentaria y sordera. Sin embargo, hay casos con familias en las cuales, a pesar de presentarse dicha asociación, no se puede diagnosticar un síndrome de Usher ni ninguno otro. Objetivo. Reevaluar fenotípicamente a 103 familias con diagnóstico previo de posible síndrome de Usher o retinitis pigmentaria asociada con sordera. Materiales y métodos. Se revisaron las historias clínicas de 103 familias con un posible diagnóstico clínico de síndrome de Usher o retinitis pigmentaria asociada con sordera. Se seleccionaron las familias cuyo diagnóstico clínico no correspondía a un síndrome de Usher típico. Los afectados fueron valorados oftalmológica y audiológicamente. Se analizaron variables demográficas y clínicas. Resultados. Se reevaluaron 14 familias cuyo diagnóstico clínico no correspondía al de síndrome de Usher. De las familias con diagnóstico inicial de síndrome de Usher típico, el 13,6 % recibieron uno posterior de "retinitis pigmentaria asociada con sordera" de "otro síntoma ocular asociado con hipoacusia',' o en forma aislada en una misma familia, de "retinitis pigmentaria" o "hipoacusia'.' Conclusiones. Es fundamental el estudio familiar en los casos en que la clínica no concuerda con el diagnóstico de síndrome de Usher típico. En los pacientes con retinitis pigmentaria asociada con sordera, el diagnóstico clínico acertado permite enfocar los análisis moleculares y, así, establecer un diagnóstico diferencial. Es necesario elaborar guías de nomenclatura en los casos con estos hallazgos atípicos para orientar a médicos e investigadores en cuanto a su correcto manejo.

ABSTRACT

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.