Related Experiment Video
Updated: Sep 11, 2025
Navigating MARRVEL, a Web-Based Tool that Integrates Human Genomics and Model Organism Genetics Information
Published on: August 15, 2019
Novel splice variants implicated in inherited retinal dystrophies in two Moroccan families
Kenza El Khair1,2, Aymane Bouzidi3, Majida Charif4
1Genomics and Human Genetics Laboratory, Institut Pasteur du Maroc, 1 Place Louis Pasteur, Casablanca, 20360, Morocco.
Background:
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 Results:
Whole 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.
Conclusion:
This 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.
Related Concept Videos
01:11Genetic Lingo
01:43Incomplete Dominance
01:20The Retinoblastoma Gene
The first-ever tumor suppressor gene called Rb was identified in retinoblastoma - a rare eye tumor in children. In inherited forms of the disease, a child inherits one defective copy of the Rb gene, which predisposes them to retinoblastoma. However,...
01:31Translation
Translation is the process of synthesizing proteins from the genetic information carried by messenger RNA (mRNA). Following transcription, it constitutes the final step in the expression of genes. This process is carried out by ribosomes, complexes of protein and specialized RNA molecules. Ribosomes, transfer RNA (tRNA), and other proteins produce a chain of amino acids—the polypeptide—as the end product of translation.
Translation Produces the Building Blocks of...
02:26Comparing Copy Number Variations and SNPs
Copy number variations or CNVs are the structural variations that cover more than 1kb of DNA sequence. The single nucleotide polymorphism (SNP), on the other hand, is a single nucleotide change or a point mutation that is found in more than 1%...
01:30Point and Frameshift Mutations