ClinVar

Description

This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 404 of the NPC1 protein (p.Arg404Trp). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with Niemann-Pick type C disease (PMID: 12955717, 26981555). ClinVar contains an entry for this variant (Variation ID: 499939). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt NPC1 protein function. This variant disrupts the p.Arg404 amino acid residue in NPC1. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 11349231, 11545687, 22065762, 26666848, 27581084). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic.