Abstract
Purpose: :
To report the inheritance mode and clinical characteristics of retinitis pigmentosa in Ningxia, an autonomous region in northwest part of China with a population of 6.5 million, about 60% Hans and 40% Hui ethnicity.
Methods: :
RP patients were recruited in Ningxia Eye Hospital during the period April 2005 to June 2011. Information of family history and marriage was documented. They all received complete ophthalmic examinations. All patients were natives of Ningxia.
Results: :
A total of 201 individuals with RP were recruited and the age ranged from 6 to 70 years. Based on the family history, 21.4% patients (20 families) were classified as ADRP and 18.4% patients (26 families) as ARRP. Over 55% patients identified as simplex RP because of lack of family history, the rest were XLRP patients. The average age of onset was 28.4±3.5 years. According to the features of fundus, 74.5% patients were classical RP and 25.5% patients were atypical RP. In atypical RP, 48.6% were retinitis pigmentosa sine pigmento. Among ARRP patients, 23 patients from 20 families reported a family history of consanguinity. The marriages of 15 families were between first cousins and 3 families were between second cousins, only 2 families were between half cousins matrimony. The average age of onset was 11.4±6.8 years. The best-corrected visual acuity (BCVA) was more than logMar 0.77 in 78.2% patients. According to the features of fundus, 13 patients were classical retinitis pigmentosa and 10 patients were retinitis pigmentosa sine pigmento. Visual field showed that all the patients had varying degrees of peripheral visual field defect. The retinal neuroepithelial layer of macular and peripheral retina became thinner and retinal photoreceptors disappeared.
Conclusions: :
The inheritance mode in Ningxia Region was similar to the report in Asia. The incidence of RP from consanguineous family was high. Consanguineous marriage is closely related with retinitis pigmentosa in Ningxia. The common features of consanguineous patients are early age of onset, rapid disease progression and severe visual impairment.
Keywords: retina • retinal degenerations: hereditary • genetics