Abstract
Purpose: :
We report the long term ocular history of a family with autosomal dominant retinitis pigmentosa (adRP) found to have a newly identified mutation of the PRPF31 gene (c.1084delA, p.Met362X in exon 11).
Methods: :
We identified 17 affected members and 4 obligate carriers that appear unaffected in a five generation family with adRP over a period of 25 years. Data regarding age of initial examination, presence of cystoid macular edema, response to therapy, associated diseases, rate of vision loss, and degree of field loss were collected. Genetic testing by eyeGENE demonstrated a new c.1084delA,p.Met362X mutation. This deletion leads to a frameshift, causing codon 362 (Met) to become a termination codon, resulting in premature protein truncation.
Results: :
Age of examination ranged from 10 to 73 years old. Three family members had severe visual field constriction at an early age and a 12-year-old had macular edema which was recalcitrant to treatment with carbonic anhydrase inhibitors. In the 73-year-old patient, visual acuity has been maintained at the 20/40 level, but Goldmann perimetry has shown progressive peripheral ring scotomata in all affected patients with progressive loss to central 5-10 degrees. ERG responses showed non-recordable scotopic response and a severely decreased photopic response in the four patients tested.
Conclusions: :
PRPF31 mutations are found in approximately 5.5% of RP patients. This family was found to have a previously unreported mutation. It is often observed that adRP is less severe than simplex RP and visual field and visual acuity are better preserved until later in life. However, we have three family members that were severely affected with visual field constriction and macular edema at an early age. The identification of novel mutations of the PRPF31 gene and clinical correlation over long term follow up has important implications for genetic counseling of affected family members, carrier testing and prenatal diagnosis. The ultimate aim of research in this area is the development of predictive tools and potential therapies for patients with this devastating disease.
Keywords: retinal degenerations: hereditary • retina • clinical (human) or epidemiologic studies: natural history