Hereditary renal-retinal dysplasia.

Abstract

Two cousins with vasopressin-resistant diabetes insipidus, progressive azotemia, and retinitis pigmentosa are presented. These patients were found in a survey of a consanguineous religious isolate, and autosomal recessive inheritance of this disorder, termed hereditary renal-retinal dysplasia, seems likely. Comparison with other similar cases from the literature suggests that this entity is distinct. Although there are superficial resemblances between hereditary renal-retinal dysplasia and two other disorders, juvenile nephronophthisis and medullary cystic disease, the fact that despite pathologic similarity all three diseases are unique when viewed from a clinicogenetic perspective is substantiated. Study of these entities suggests that reliance solely on the pathologic picture for classification of various hereditary renal disorders may lead to diagnostic confusion. The presence of extrarenal manifestations of the defective genes may be of paramount importance in the differential diagnosis of two functionally and histologically similar renal disorders.