Restrictive cardiomyopathy (RCM) is very rare in children and usually associated with a poor prognosis. Identification and thorough diagnostic work-up are essential. We report the case of a 3 year old previously well girl, who was referred to A&E with shortness of breath. On admission, she was found to be in acute heart failure.
Echocardiography showed a restrictive cardiomyopathy and a very large pericardial effusion which was subsequently drained. A full cardiomyopathy screen was performed but all her metabolic indices were normal. Genetic investigations identified a novel MYH7 variant. The MYH7 gene is usually associated with hypertrophic cardiomyopathy. This patient is the second in the world in whom RCM has resulted from a variant invariant in MYH7, the first with a phenotypic effect and provides further evidence that this gene is linked with different cardiac phenotypes.