A Novel Missense Variant C.2571 (P.Ala857=) of the DHX38 Gene in a Saudi Family Causes an Autosomal Recessive Retinitis Pigmentosa

We present two cases of a novel missense variant mutation in the DHX38 gene, which is associated with autosomal recessive retinitis pigmentosa (RP) in two Saudi sisters who presented with poor visual acuity since childhood. On initial examination, the best-corrected visual acuity was 20/300 in both eyes for the two sisters. Fundus examination revealed widespread retinal pigmentary changes, linear peripheral hyperpigmentation clumps, bone spicules, and bilateral optic nerve drusen with bilateral macular hyperpigmentation. Spectral-domain optical coherence tomography scans reveal losses of the outer retinal layer and the presence of subretinal fibrosis and thinning of the choroid. Molecular sequencing analysis of the DHX38 exome identified a novel missense mutation of the homozygous variant c. 2571 (p. Ala857=), which co-segregates with the autosomal recessive RP gene that encodes the premRNA splicing factor, PRP16. The aim of this report is to describe the clinical feature associated with this variant and to provide additional evidence that DHX38 is involved in RP. To the best of our knowledge, this variant has not been described in the literature.