A novel FLNC variation associated with restrictive cardiomyopathy with an unusually long clinical course — A case report

Restrictive cardiomyopathy (RCM) is a rare disease with varied aetiology. It is characterized by restrictive ventricular physiology leading to diastolic dysfunction and heart failure. Although the genetic background of the disease is poorly understood, idiopathic RCM is primarily a genetic disease with rapid disease progression and a poor prognosis. We used a targeted cardiomyopathy gene panel to identify a novel heterozygous filamin-C (FLNC) variant, NM_001458.5: c.3551G>T; p.Gly1184Val, in a patient from India. Although there are no specific treatment guidelines, our patient was successfully treated with loop diuretics, oral anticoagulation and mineralocorticoid receptor antagonists. We believe that the early medical intervention improved the patient's quality of life and led to favourable disease progression. We describe a RCM phenotype with an unusually long clinical course demonstrating the disease's progressive nature for over 18 years, which is likely associated with this novel variant. Our report also outlines the importance of considering genetic testing early during the diagnostic workup of idiopathic RCM cases.