Novel frameshift Variant c.3056delA of the DHX38 Gene in a Chinese Family With Retinitis Pigmentosa

Abstract

Abstract Background Retinitis pigmentosa (RP) is the most common inherited retinal degeneration. Our purpose was to describe disease-causing variants in a Chinese patient with RP. We described the clinical features and identify a novel (p.Lys1019fs) variant in DHX38.Case presentation A 47-year-old Chinese man complained of persistent visual impairment. To clarify the diagnosis, the clinical symptoms were observed and analysed in combination with comprehensive ophthalmologic examinations and genetic analysis. Abnormal fundus manifestations were found, including thinning of retinal arteriovenous vessels, obscure reflection in macular fovea, and scattered osteocyte-like pigment in the retina. We identified two mutations of USH2A gene (c.2802T > G and c.8559-2A > G ) and one novel mutation of DHX38 gene (c.3056delA) in the proband. The parents with visual loss were heterozygous carriers. The compound heterozygous mutations in USH2A are the underlying cause of this case. And the novel variant results in the mutation of amino acid 1019 from lysine to arginine and bring a new reading frame, the 37th codon followed by the mutation site turn to be a stop codon, resulting in a premature protein truncation.Conclusions The study identified two compound heterozygous USH2A variants (c.2802T > G and c.8559-2A > G) and one novel DHX38 variants (c.3056delA) in an RP patient. It is conducive to a clearer understanding of genotype-phenotype correlation in the non-syndromic RP patients. Our study expands the spectrum of DHX38 variants in RP as well.