Clinical Report |
Title:
|
The frequency of familial dilated cardiomyopathy in a series of patients with idiopathic dilated cardiomyopathy. |
Authors: |
Michels VV, Moll PP, Miller FA, Tajik J, Chu JS, Driscoll DJ, Burnett JC, Rodeheffer RJ, Chesebro JH, and Tazelaar HD. |
Journal: |
New Engl J Med, 1992;326:77-82. |
| Department of Medical Genetics, Mayo Clinic, Rochester, Minn. | |
PubMed Link: |
PMID: 1727235 |
Citation Type: |
phenotype (clinical data only). |
Study Design: |
prospective study of first degree relatives of patients with idiopathic dilated cardiomyopathy. |
Study Measurements: |
echocardiography, ECG. |
Summary: |
Virginia Michels and colleagues at the Mayo Clinic demonstrated that dilated cardiomyopathy was a familial disease in 20% of subjects diagnosed with IDC. Inclusion criteria included an echocardiographic diastolic dimension >95th percentile for the patient's age and body surface area and a left ventricular ejection fraction <50%. All patients >40 years of age underwent coronary angiography to exclude coronary artery disease as the etiology of their dilated cardiomyopathy. Ninety-six patients were identified by chart review and 59 (61%) agreed to participate and had their relatives enrolled for study. A total of 315 relatives were prospectively screened. Familial disease was shown to be present in 12 of these 59 index patients (20%), with 18 relatives found to be affected with disease. Of these, 6 had symptoms and 12 were asymptomatic. Fifteen patients were given new diagnoses (7 known to have heart disease, 8 with no previously known heart disease). Of the 20% of individuals initially diagnosed with IDC who were eventually assigned to FDC, only 5% had been suspected of having familial disease based on family history alone. Finally, 22 of 240 (9.2%) relatives with normal ejection fractions had increased left ventricular systolic and/or diastolic dimensions compared to 2 of 112 (1.8%) healthy control subjects (p < 0.02). This finding indicated that asymptomatic left ventricular enlargement was the earliest marker for familial dilated cardiomyopathy. Complex segregation analysis of the families suggested a single dominant locus with incomplete penetrance. |
Comment: |
In 1992 this study provided the most compelling evidence that IDC could be familial, and likely genetic, is some proportion of cases of IDC. |