Lamin A/C gene (LMNA)-related familial dilated cardiomyopathy (fDCM) is an aggressive heart disease that often leads to transplantation and sudden death.
The LMNA gene, which encodes the nuclear envelope protein lamin A/C, is considered to be the most common autosomal disease gene associated with familial dilated cardiomyopathy.
We identified an autosomal dominant non‐sense mutation (R225X) in exon 4 of the lamin A/C (LMNA) gene in a Chinese family spanning 3 generations with familial dilated cardiomyopathy (DCM).
The results of two more recent studies identify two additional human disease-associated proteins that are sumoylated, amyloid precursor protein (APP), and lamin A. APP sumoylation modulates Aβ peptide levels, suggesting a potential role in Alzheimer's disease, and decreased lamin A sumoylation due to mutations near its SUMO site has been implicated in causing some forms of familial dilated cardiomyopathy.
Mutations in the lamin A/C gene (LMNA) are established causes of familial dilated cardiomyopathy (DCM) with atrio-ventricular block although relatively little is known about genotype-phenotype correlations.
Familial dilated cardiomyopathy with conduction system defects variably associated with skeletal muscle abnormalities is frequently caused by LMNA gene mutations.
These findings point to a function for sumoylation in modulating amyloid-beta peptide levels, indicating a potential role in Alzheimer's disease, and for decreased lamin A sumoylation as a causative factor in familial dilated cardiomyopathy.
Sequencing of the LMNA exons revealed one missense mutation at C568T (Arg190Trp) in the alpha-helical rod domain of the LMNA gene co-segregating with FDC with conduction-system disease.
We used mutation detection to evaluate the lamin A/C gene in a 45 year-old woman with familial dilated cardiomyopathy and conduction system disease whose family has been well characterized for this phenotype 1.
Knowledge of such correlations may help to further define the mechanisms of disease in LMNA-associated FDC and can assist in the monitoring of disease for at-risk family members.
To date, 2 genes for X-linked familial dilated cardiomyopathy (dystrophin, G4.5) have been identified and 4 genes for the autosomal dominant form (actin, desmin, lamin A/C, delta-sarcoglycan) have been described.