Rare RNF213 variants and the risk of intracranial artery stenosis/occlusion disease in Chinese population: a case-control study.

BACKGROUND: RNF213 rare variant-p.R4810K (rs112735431) was significantly associated with intracranial artery stenosis/occlusion disease (ICASO) in Japan and Korea and to a lesser degree in China. Considering the allelic heterogeneity, we performed target exome sequencing of RNF213 with the aim to identify the rare variants spectrum and their association with ICASO in a Chinese population and further to explore whether the rare variants carrier patients present specific clinical phenotype.

METHODS: Target exome sequencing of RNF213 was performed in 250 ICASO patients using FastTarget sequencing technology. Various filtering process were used to select the candidate variants. Control individuals were obtain from 1000 Genome Project (208 Chinese samples) and GeneSky in-house database (1007 samples). Gene-based association analyses were conducted to identify the association between RNF213 rare variants and ICASO. The clinical characteristics of rare variant carriers and non-carriers were compared using Chi-squared test or Fisher's exact test.

RESULTS: After filtration, 18 rare variants were identified in 39 patients. Gene-based association test showed that rare variants of RNF213 were significantly associated with ICASO (Minor allele frequency < 0.05, WSS p = 4.88 × 10- 10 ; SKAT p = 9.68 × 10- 6 ; SKAT-O p = 3.42 × 10- 9 ). There were no significant clinical characteristic differences other than the diagnosis age which was older in the carriers than the non-carriers (60.5 ± 6.2 vs 57.3 ± 8.9 years old, p = 0.028).

CONCLUSION: Rare variants of RNF213 are associated with ICASO in Chinese. However, there are limited genetic diagnosis values of the gene due to no specific phenotypic presentation in the carriers and non carrier patients.