Potential resistance to SARS-CoV-2 infection in lysosomal storage disorders

Founder mutations and rare disease in the Arab world

Founder mutations are disease-causing variants that occur frequently in geographically or culturally isolated groups whose shared ancestor(s) carried the pathogenic variant. While some disease alleles may vanish from the genetic pool due to natural selection, variants with weaker effects may survive for a long time, thereby enhancing the prevalence of some rare diseases. These are predominantly autosomal recessive diseases but can also be autosomal dominant traits with late-onset or mild phenotypes. Cultural practices, such as endogamy and consanguinity, in these isolated groups lead to higher prevalence of such rare diseases compared to the rest of the population and worldwide. In this Perspective, we define population isolates and the underlying genetic mechanisms for accumulating founder mutations. We also discuss the current and potential scientific, clinical and public-health implications of studying founder mutations in population isolates around the world, with a particular focus on the Arab population.

"Every Cloud Has a Silver Lining": How Three Rare Diseases Defend Themselves from COVID-19 and What We Have Learnt from It

The process of SARS-CoV-2 infection, responsible for the COVID-19 pandemic, is carried out through different steps, with the interaction between ACE2 and Spike protein (S) being crucial. Besides of that, the acidic environment of endosomes seems to play a relevant role in the virus uptake into cells and its intracellular replication. Patients affected by two rare genetic tubulopathies, Gitelman's and Bartter's Syndromes, and a rare genetic metabolic disease, Fabry Disease, have shown intrinsic protection from SARS-CoV-2 infection and COVID-19 on account of specific intrinsic features that interfere with the virus uptake into cells and its intracellular replication, which will be reported and discussed in this paper, providing interesting insights for present and future research.

Biochemical Mechanisms beyond Glycosphingolipid Accumulation in Fabry Disease: Might They Provide Additional Therapeutic Treatments?

Fabry disease is a rare X-linked disease characterized by deficient expression and activity of alpha-galactosidase A (α-GalA) with consequent lysosomal accumulation of glycosphingolipid in various organs. Currently, enzyme replacement therapy is the cornerstone of the treatment of all Fabry patients, although in the long-term it fails to completely halt the disease's progression. This suggests on one hand that the adverse outcomes cannot be justified only by the lysosomal accumulation of glycosphingolipids and on the other that additional therapies targeted at specific secondary mechanisms might contribute to halt the progression of cardiac, cerebrovascular, and renal disease that occur in Fabry patients. Several studies reported how secondary biochemical processes beyond Gb3 and lyso-Gb3 accumulation-such as oxidative stress, compromised energy metabolism, altered membrane lipid, disturbed cellular trafficking, and impaired autophagy-might exacerbate Fabry disease adverse outcomes. This review aims to summarize the current knowledge of these pathogenetic intracellular mechanisms in Fabry disease, which might suggest novel additional strategies for its treatment.