Any familial isolated dilated cardiomyopathy in which the cause of the disease is a mutation in the SCN5A gene.

Any hypertrophic cardiomyopathy in which the cause of the disease is a mutation in the MYL2 gene.

Any familial isolated dilated cardiomyopathy in which the cause of the disease is a mutation in the ACTN2 gene.

Ogden syndrome (OGDNS) is an X-linked neurodevelopmental disorder characterized by postnatal growth failure, severely delayed psychomotor development, variable dysmorphic features, and hypotonia. Many patients also have cardiac malformations or arrhythmias (summary by Popp et al., 2015).

Atrial fibrillation (AF) is a supraventricular tachyarrhythmia characterized by uncoordinated atrial activation with consequent deterioration of atrial mechanical function. It is the most common sustained cardiac rhythm disturbance, and its prevalence increases as the population ages. An estimated 70,000 strokes each year are caused by atrial fibrillation (summary by Oberti et al., 2004). For a discussion of genetic heterogeneity of atrial fibrillation, see 608583.

Lipid storage myopathy due to FLAD1 deficiency is an autosomal recessive inborn error of metabolism that includes variable mitochondrial dysfunction. The phenotype is extremely heterogeneous: some patients have a severe disorder with onset in infancy and cardiac and respiratory insufficiency resulting in early death, whereas others have a milder course with onset of muscle weakness in adulthood. Some patients show significant improvement with riboflavin treatment (summary by Olsen et al., 2016).