Beyond the NMD Boundary: Characterizing the Phenotypes of C-terminal CDH1 Mutations

Session:
#597
Date:
Friday, Oct 20, 2017 11:30am – 12:30pm
Conference:
ASHG 2017
Authors:
Adam Chamberlin, Carin Espenschied, Ira Lu, Kate Krempely, Rachid Karam, PhD
  • C-terminal truncating alterations in CDH1 escape the nonsense-mediated mRNA pathway. It’s possible that these truncated proteins retain partial function, and variants in this region must be interpreted with caution.
  • Using clinical data, molecular evidence, and structural information, we characterized truncating alterations in the CDH1 gene that were identified downstream of the NMD boundary in a large diagnostic laboratory cohort of ~400,000 alleles.
  • We reported three pathogenic C-terminal truncations in families meeting International Gastric Cancer Linkage Consortium (IGCLC) diagnostic criteria. Additionally, we identified the most C-terminal pathogenic mutation in our cohort, which occurred de novo in an individual with lobular breast cancer. Identifying the most C-terminal mutation allows us to classify other, upstream C-terminal truncating alterations as pathogenic or likely pathogenic.