[Mutation of the lamin A/C gene associated with left ventricular apical hypoplasia: a new phenotype for laminopathies?].

Isolated left ventricular (LV) apical hypoplasia is a rare anomaly characterized by a dysfunctioning, spherical left ventricle and elongated right ventricle wrapping around the deficient LV apex. The etiology is unknown; it is presumed to be a rare congenital developmental defect during partitioning of the ventricles, caused by an in-utero infection. We describe for the first time a case of isolated LV apical hypoplasia associated with lamin A/C gene mutation. Echocardiography showed a mildly dilated left ventricle with spherical configuration and impaired systolic function, and an elongated right ventricle wrapping around the deficient LV apex. Magnetic resonance imaging also identified fatty replacement of the LV apical myocardium. Late gadolinium enhancement imaging showed mid-wall fibrosis in the interventricular septum. Family screening by ECG and echocardiography failed to identify heart disease in the patient's family; however, the proband's father and daughter were found to carry the same mutation. This case report highlights the difficulties of a correct interpretation of genetic mutations in a single patient with cardiomyopathy. Indeed, the causative role of a mutation needs to be confirmed by co-segregation analysis. Although the etiology of LV apical hypoplasia remains unknown, the first hypothesis is an acquired process interfering with the early development of the heart, the new one is a genetic defect.