ClinVar

Description

Variant summary: TPP1 c.379C>T (p.Arg127X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant allele was found at a frequency of 6.4e-05 in 251478 control chromosomes. This frequency is not significantly higher than expected for a pathogenic variant in TPP1 causing Neuronal Ceroid-Lipofuscinosis (Batten Disease) (6.4e-05 vs 0.003), allowing no conclusion about variant significance. c.379C>T has been reported in the literature in at-least two individuals affected with Neuronal Ceroid-Lipofuscinosis (Batten Disease)(Sleat_1999, Scocchia_2019). These data indicate that the variant is likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic.