Cardiac penetrance was high in young asymptomatic LMNA genotype-positive family members with frequent AV block and VT, highlighting the importance of early family screening and cardiological follow-up.
Mutations in LMNA are variably expressed and may cause cardiomyopathy, atrioventricular block (AVB), or atrial arrhythmias (AAs) and ventricular arrhythmias (VA).
Localized fibrosis in the interventricular septum may be the mechanism behind reduced septal function, atrioventricular block and VA in Lamin A/C mutation-positive subjects.
The aim of this study was to investigate ultrastructural nuclear membrane changes by conventional electron microscopy and protein expression by immuno-electron microscopy in the heart of patients with DCM and AVB due to LMNA gene mutations.
Five novel LMNA mutations (K97E, E111X, R190W, E317K, four base pair insertion at 1,713 cDNA) were identified in five cases of familial autosomal dominant DCM with AVB (5/15: 33%).