Background: Wolfram syndrome (WFS) is an autosomal recessive disorder that often leads to diabetes, optic atrophy, and sensorineural hearing loss. The aim of this study was to determine the clinical characteristics and the genetic cause of the first two Moroccan families presenting with WFS. Methods: The clinical features of five members of two WFS families were evaluated. Whole-exome sequencing was conducted to explore the underlying genetic cause in the affected patients. Results: Two homozygous variants in the WFS1 gene were identified, each in one of the two families studied: a missense c.1329C>G variant (p.Ser443Arg) and a nonsense mutation c.1113G>A (p.Trp371Ter). These variants affected conserved amino acid residues, segregated well in the two families, and are absent from genetic databases and in controls of Moroccan origin. Bioinformatics analysis classified the two variants as pathogenic by in silico tools and molecular modeling. Conclusion: Our study identified for the first time two variants in Moroccan patients with WFS that extends the mutational spectrum associated with the disease.
Membrane Proteins , Mutation, Missense , Pedigree , Wolfram Syndrome , Adolescent , Adult , Child , Female , Humans , Male , Codon, Nonsense/genetics , Exome Sequencing/methods , Homozygote , Membrane Proteins/genetics , Morocco , Mutation , Mutation, Missense/genetics , Wolfram Syndrome/genetics , Young Adult
Infection by the recent SARS-CoV-2 virus causes the COVID-19 disease with variable clinical manifestations ranging from asymptomatic or mild respiratory symptoms to severe respiratory distress and multiorgan failure. The renin-angiotensin system, responsible for maintaining homeostasis and governing several critical processes, has been considered the main system involved in the pathogenesis and progression of COVID-19. Here, we aimed to assess the possible association between variants in the RAS-related genes and COVID-19 susceptibility and severity in a sample of the Moroccan population. A total of 325 individuals were recruited in this study, with 102 outpatients, 105 hospitalized patients, and 118 healthy controls negative for SARS-CoV-2 infection, and subjected to NGS gene panel sequencing containing eleven RAS pathway genes. A total of 65 functional variants were identified, including 63 missenses, 1 splice, and 1 INDEL. Most of them were rare, with 47 (72%) found in a single individual. According to the common disease/common variant hypothesis, five common candidate variants with MAF > 10% were identified (ACE2 rs2285666, TMPRSS2 rs12329760, AGT rs699 genes, ACE rs4341, and ACE rs4343). Statistical analysis showed that the ACE rs4343 AA genotype was associated with a 2.5-fold increased risk of severe COVID-19 (p = 0.026), and the T genotype of the ACE2 rs2285666 variant showed a borderline association with susceptibility to SARS-CoV-2 in males (p = 0.097). In conclusion, our results showed that the RAS pathway genes are highly conserved among Moroccans, and most of the identified variants are rare. Among the common variants, the ACE rs4343 polymorphism would lead to a genetic predisposition for severe COVID-19.
