Related Experiment Videos
Cardiac involvement in Becker muscular dystrophy
P Melacini1, M Fanin, G A Danieli
1Department of Cardiology, University of Padua, Italy.
Insights
Becker muscular dystrophy frequently causes heart problems, particularly early right ventricular dysfunction. Specific gene deletions, like exon 49, are strongly linked to cardiac disease in these patients.
Area of Science:
- Cardiology
- Genetics
- Neuromuscular Disorders
Background:
- Becker muscular dystrophy (BMD) arises from dystrophin gene mutations affecting heart and skeletal muscles.
- Cardiac and skeletal muscle symptoms are key clinical manifestations of BMD.
Purpose of the Study:
- To determine the incidence of myocardial involvement in BMD.
- To investigate the relationship between cardiac disease and specific molecular defects (DNA or protein level) in BMD.
Main Methods:
- Thirty-one BMD patients underwent ECG, echocardiography, and 24-hour Holter monitoring.
- Diagnosis confirmed via neurologic exam, dystrophin analysis (immunohistochemistry/Western blot), and DNA analysis.
Main Results:
- Abnormal ECG (68%) and echocardiograms (62%) were common. Right ventricular involvement occurred in 52% of patients.
- Left ventricular impairment was seen in 10% (isolated) or 29% (with RV dysfunction). RV disease appeared in teenagers, LV in older patients.
- Exon 49 deletion consistently correlated with cardiac involvement; exon 48 deletion was associated in all but two patients. No correlation found between skeletal muscle disease, cardiac issues, and dystrophin abnormalities.
Conclusions:
- Cardiac manifestations in BMD typically involve early right ventricular dysfunction, potentially with left ventricular impairment.
- Exon 49 deletion is a significant genetic marker associated with cardiac disease in Becker muscular dystrophy.
Objectives:
The purpose of this study was to assess the incidence of myocardial involvement and the relation of cardiac disease to the molecular defect at the deoxyribonucleic acid (DNA) or protein level in Becker muscular dystrophy.
Background:
Dystrophin gene mutations produce clinical manifestations of disease in the heart and skeletal muscle of patients with Becker muscular dystrophy.
Methods:
Thirty-one patients underwent electrocardiographic and echocardiographic examination and 24-h Holter monitoring. The diagnosis was established by neurologic examination, dystrophin immunohistochemical assays or Western blot on muscle biopsy, or both, and DNA analysis.
Results:
Electrocardiographic and echocardiographic findings were abnormal in 68% and 62% of the patients, respectively. Right ventricular involvement was detected in 52%. Left ventricular impairment was observed either as an isolated phenomenon (10%) or in association with right ventricular dysfunction (29%). Right ventricular disease was manifested in the teenagers, and an impairment of the left ventricle was observed in older patients. Right ventricular end-diastolic volumes were significantly increased compared with those in a control group. The left ventricular ejection fraction was significantly lower in older patients than in control subjects or younger patients. Life-threatening ventricular arrhythmias were detected in four patients. No correlations were found between skeletal muscle disease, cardiac involvement and dystrophin abnormalities. In our patients, exon 49 deletion was invariably associated with cardiac involvement. Exon 48 deletion was associated with cardiac disease in all but two patients.
Conclusions:
The cardiac manifestation of Becker muscular dystrophy is characterized by early right ventricular involvement associated or not with left ventricular impairment. Exon 49 deletion is associated with cardiac disease.