Lamin A/C deficiency as a cause of familial dilated cardiomyopathy.

PURPOSE OF REVIEW

Familial dilated cardiomyopathy is an underrecognized form of dilated cardiomyopathy. Lamin A/C deficiency is probably the most common cause of familial dilated cardiomyopathy. This review will focus on the emerging knowledge of epidemiology, diagnosis, and treatment of patients with lamin A/C deficiency, as well as possible disease mechanisms.

RECENT FINDINGS

Screening of patients with dilated cardiomyopathy continues to indicate that lamin A/C deficiency is a significant cause. Multiple novel mutations have been found, suggesting that many mutations are limited to individuals or families. It is unknown how mutations cause the syndrome, although an animal model has shown that lamin A/C insufficiency causes apoptosis, particularly in the conduction system. Inheritance is predominantly autosomal dominant, but penetrance is variable. For symptomatic patients, the course is malignant, with conduction system disease, atrial fibrillation, heart failure, and sudden cardiac death. The data are contradictory, and currently, there is no clear marker for when a lamin A/C-deficient patient is at risk for sudden death.

SUMMARY

Lamin A/C deficiency is an important cause of dilated cardiomyopathy, and diagnosis requires that clinicians have a high index of suspicion. Our knowledge of the mechanisms, diagnosis, and treatment of lamin A/C deficiency is incomplete. It is clear that patients with this condition have a malignant course and need to be followed aggressively.