RP1 mutation are involved in the progression of primary congenital glaucoma

Background: Primary congenital glaucoma (PCG) is a severe blinding ocular disorder with an incompletely understood pathogenesis. Genetic and genomic studies, including Family-Based Variant Filtering, are contributing to identifying novel loci associated with glaucoma to enrich the knowledge about glaucoma genetic susceptibility. Moreover, high-throughput functional genomics contributes to defining the relevance of genetic results in the biological pathways and processes involved in glaucoma pathogenesis. This study is expected to advance significantly our understanding of glaucoma's genetic basis and provide new druggable targets to treat glaucoma.Methods: We have collected 8 PCG related clinical peripheral blood samples from four families in the Xinjiang region. Whole exome sequencing was conducted to identify pathogenic genes and mutations. Gene Ontology and KEGG enrichment analyses were conducted on mutated genes. Sanger sequencing was used to verify whether COS7 cells had a SNP mutation (C>T) at the endogenous chr8:54720202 locus. qRT-PCR was utilized to measure three RP1 transcripts levels in COS7 cells. Furthermore, we validated the effects of RP1 mutation on COS7 cells at the cellular level.Results: Through the analysis of susceptible alleles from the family, we identified a shared homozygous RP1 mutation site (C>T) at chr8:54720202 across four family samples. Additionally, the most significant biochemical metabolic pathways and signaling pathways involved by mutated genes included Hypertrophic cardiomyopathy (HCM), Arrhythmogenic right ventricular cardiomyopathy (ARVC), Dilated cardiomyopathy (DCM), Focal adhesion, and PI3K-Akt signaling pathway. According to the mainly wildtype RP1 transcript (ENST00000636932.1) was expressed in COS7 cells, chr8:54720202 site-directed mutation not only led to RP1 mRNA and protein up-expression, but also reduced cell proliferation and migration, and increased apoptosis. Further research revealed RP1 mutation localized to the nucleus and altered expression of GRP78 (BIP), PDI, MMP2, and NAP1L1.Conclusions: RP1 mutation were involved in the progression of PCG, offering novel insights for the precise diagnosis and treatment of PCG.