AUTOSOMAL RECESSIVE RETINITIS-PIGMENTOSA WITH PRESERVED PARA-ARTERIOLAR RETINAL-PIGMENT EPITHELIUM

Retinitis pigmentosa with preserved para-arteriolar retinal pigment ep ithelium is a rare form of retinitis pigmentosa that starts early in l ife with preservation of retinal pigment epithelium adjacent to and un der the retinal arterioles and that has hitherto been described as an isolated form. We examined 22 patients from one large family, together with two isolated patients, and confirmed the presumed autosomal rece ssive mode of inheritance in this type of retinitis pigmentosa. New fi ndings associated with retinitis pigmentosa with preserved para-arteri olar retinal pigment epithelium were asteroid hyalosis in four (17%) o f 24 patients, tortuosity of retinal arterioles in 11 (46%) of 24 pati ents, peripheral regions of opacified vessels in eight (33%) of 24 pat ients, and preservation not only of the para-arteriolar pigment epithe lium, but also of the peripheral retinal pigment epithelium in 13 (54% ) of 24 patients. Previously reported signs present in these patients were nystagmus in six (25%) of 24 patients, hypermetropia in 23 (96%) of 24 patients, optic nerve head drusen in nine (38%) of 24 patients, vascular sheathing in 11 (46%) of 24 patients, maculopathy in all 24 p atients (100%), yellow round deposits in the posterior pole in nine (3 8%) of 24 patients, exudates resembling those in Coats' disease in two (8%) of 24 patients, visual field defects in all 24 patients (100%), and nondeductible electroretinograms in 21 (91%) of 23 patients. Linka ge analysis carried out in the large family resulted in the assignment of a gene for retinitis pigmentosa with preserved para-arteriolar ret inal pigment epithelium to chromosome 1q31-q32.1.