NPHS1 and familial nephrotic syndrome: Contrary to this case, although patients with Finnish congenital nephrotic syndrome (FCNS) carrying the mutation c.3325C > T, p.R1109X in NPHS1, present the same severe phenotype, we speculate that the decrease in the thermodynamic stability of the RNA G4 may reduce the affinity of some RNA binding proteins (RBPs) that act to unwind these structures, leading to a decrease in the pre-mRNA splicing efficiency.