Novel splice variants implicated in inherited retinal dystrophies in two Moroccan families
摘要
Inherited retinal dystrophies (IRD) are a group of conditions resulting in visual impairments or blindness, due to the dysfunction of the retina. It affects 1/2000 individuals worldwide, and over 324 genes and 20 phenotypes are implicated in these pathologies. The most common form of IRD is Retinitis Pigmentosa, followed by Stargardt diseases, Leber congenital amaurosis and cone/cone-rod dystrophies. Each form of IRDs presents different clinical features. This study aims to broaden the clinical and genetic investigations of IRD patients in Morocco.
Methods and resultsWhole exome sequencing was performed on the probands of two unrelated Moroccan families with IRD phenotypes, followed by Sanger sequencing to evaluate the segregation of candidate variants within family members. WES revealed two homozygous pathogenic splice-variants in CABP4:c.800–2 A > G and TTLL5:c.182-1G > T in the two families, and was confirmed by Sanger sequencing that revealed a second homozygous variant in TTLL5 c.182-5T > C in the second family. All parents were heterozygous.
ConclusionThis study reports novel pathogenic variants in TTLL5 and CABP4 in patients with IRDs. These findings expand our knowledge of IRD causal genes in Moroccan patients.