Genetic Testing in Cardiomyopathies: Do we need to redefine the UK National testing criteria?

​​​Authors

Andrew C. Madu1, Anthony D. Dimarco1, Amy Hardy-Wallace1, Henry O. Savage1,2, Jason N. Dungu1,2

​

Affiliations

1. Basildon University Hospital, Mid and South Essex NHS Foundation Trust, Nethermayne, Basildon, Essex, SS16 5NL, UK

2. Anglia Ruskin University, School of Medicine, Chelmsford, Essex, CM1 1SQ, UK

​

Background: Inherited cardiac conditions, including dilated cardiomyopathy (DCM) and hypertrophic cardiomyopathy (HCM), may have a monogenic cause identified through genetic testing (GT). Confirmation of pathogenic gene variants can have important implications for the patient and their relatives. The UK National Genomic Test Directory (NGTD) provides strict criteria on the indications for genetic testing; however, the European Society of Cardiology (ESC) recommend wider GT. We reviewed the prevalence of pathogenic genotypes in patients undergoing genetic testing who did not meet the NGTD criteria.

 

Methods: We conducted a retrospective analysis of patients who underwent GT with a confirmed diagnosis of HCM or DCM attending the Essex Inherited Cardiac Conditions (ICC) Clinic between January 2023 and January 2025.

 

Results: 259 patients were included in the analysis with DCM representing 52.5% (n = 136) and HCM accounting for 47.5% (n = 123) of the total cohort. The diagnostic yield of genetic testing was 19.9% in DCM and 18.7% in HCM (p = 0.23).

18.5% of gene positive DCM patients and 27.1% of gene positive HCM patients did not meet current UK testing criteria (p = 0.73), predominantly due to age at diagnosis. All gene positive patients in the DCM subgroup not meeting current NGTD criteria for testing had evidence of myocardial fibrosis (Figure 1).

 

​