Abstract
Purpose :
Retinitis pigmentosa (RP) is a clinically and genetically heterogeneous group of retinal dystrophies. PRPF31 and SNRNP200 are known to be causative genes for autosomal dominant RP (adRP) and are involved in pre-mRNA splicing. We performed a retrospective observational clinical study to assess the long-term clinical course of Japanese patients with RP caused by mutations in pre-mRNA splicing gene.
Methods :
We clinically examined three unrelated male Japanese patients with RP who received care and follow-up in our hospital, and collected their blood samples. Ophthalmic examinations, including best-corrected visual acuity (BCVA), Goldmann perimetry, fundus photography, and full-field electroretinography (ERG) were also performed. BCVA and visual field were continuously monitored. Visual field areas were quantified via ImageJ software and compared with normal areas. To identify causative mutations, 74 genes known to cause RP or Leber congenital amaurosis were examined via targeted next-generation sequencing.
Results :
Mutation analysis revealed the cause of adRP to be heterozygous PRPF31 mutations [p.(R354*) and p.(S145Pfs*8)] in two patients and a heterozygous SNRNP200 mutation [p.(S1087L)] in one patient. The patients’ current age range was 18-36 years, and the observation period was between 15 and 30 years. The onset of nyctalopia occurred in the first decade and fundus findings were typical of RP in all patients. Rod responses on ERG were non-recordable in patients with PRPF31 mutations and severely reduced in the patient with an SNRNP200 mutation. The clinical courses of both patients with PRPF31 mutations were similar. Although BCVA was relatively preserved even into the fourth decade, the visual field area exhibited rapid deterioration in their mid-teens with severe concentric constriction of 10° from fixation in the third decade (Fig. 1). The patient with an SNRNP200 mutation had strabismic amblyopia in his right eye, though he retained BCVA and visual field in his second decade (Fig. 1).
Conclusions :
Rapid deterioration of visual field early in life was seen in patients with a PRPF31 mutation. These findings reported herein may ultimately play a role in the provision of high-quality counseling for patients with this condition.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.