NMNAT1 mutation causing retinitis pigmentosa

individuals affected with CRD. DNA sample from the index patient was undergone to whole exome sequencing (WES). Results: The index patient was 30 years old and reported night blindness at the age of ten. Visual acuity was limited to 1/10 in right and left eyes. Fundus examination revealed beaten-bronze aspect of the macula, peripheral retinal pigment epithelium atrophy, mild optic atrophy and narrowing of the vessels. Electroretinogram showed altered scotopic and photopic responses. The sister, aged 32, had the same fundus presentation. An affected cousin had on fundus examination gliosis of the posterior pole with diffuse retinal atrophy. Molecular analysis shown that the index patient carry novel homozygous splice-site mutation (NM_177965: c.470+1G>T) in C8ORF37. The missense variant located in the donor splice side of intron 6 was not reported in the ExAC and genomAD. Conclusions: We describe a novel mutation in C8orf37, coding to a ciliary cytoplasmic protein. Our patients showed phenotype variability depending on age; at the third decade patients had beaten-bronze aspect of the macula, peripheral RPE atrophy, mild optic atrophy and narrowing of the vessels. At the fifth decade, we found gliosis of the posterior pole better visualized on OCT with diffuse retinal atrophy.