Purpose: Retinitis pigmentosa (RP) is an intractable disease and no effective treatment currently exists; therefore, it is crucial to develop promising therapeutic approaches for RP. To accelerate basic and clinical research related to RP, we initiated the Japan Retinitis Pigmentosa Registry Project (JRPRP), which is a patient registry for RP and RP-related diseases in Japan. In this study, we report the current status of JRPRP and analyze the clinical data of the registered patients.
Patients and methods: We collected case records from 1817 patients registered in JRPRP between July 2018 and March 2020 and analyzed their clinical characteristics.
Results: In total, 1817 patients (851 men and 966 women) were registered by 13 of the 25 facilities participating in JRPRP. Mean patient age was 55.0±17.4 years. The diagnoses were as follows: typical RP (n=1563 patients), cone-rod dystrophy (n=62), RP sine pigmento (n=59), central or pericentral RP (n=37), Bietti crystalline corneoretinal dystrophy (n=18), Usher syndrome (n=15), choroideremia (n=14), others (n=34), and unknown (n=15). Inheritance pattern analysis revealed that 12.7% of the cases were autosomal dominant, 18.5% were autosomal recessive, 1.7% were X-linked, 64.3% were sporadic, and 2.9% were unknown. Among the typical RP cases, the diagnostic rate of causative genes was 44.3%, and the most common mutation was that of EYS. Patients with EYS mutations had better visual acuity than those with other mutations in the autosomal recessive inheritance pattern.
Conclusions: The frequencies of the inheritance pattern registered in JRPRP were similar to those in previous reports from Japan. The EYS mutation was the most common causative factor. The ongoing accumulation of JRPRP data will further clarify the clinical characteristics of RP patients in Japan.
Nippon Ganka Gakkai Zasshi (J Jpn Ophthalmol Soc) 125: 425-430, 2021.