Abstract 11621: Fibrillin-1 Gene Mutations in Left Ventricular Non-Compaction Cardiomyopathy

Abstract

Introduction: Left ventricular non-compaction cardiomyopathy (LVNC) is a rare and unique cardiomyopathy. Its presentation can range from a benign phenotype to overt heart failure and sudden cardiac death. The genetics of LVNC are not completely understood and current genetic testing has a yield of about 30% in identifying a causative gene mutation. We present a series of patients with LVNC and fibrillin-1 (FBN1) gene mutations. Hypothesis: We hypothesize that FBN1 gene mutations can lead to LVNC by way of its role in the myocardial extracellular matrix during cardiac development. Methods: A retrospective review of all patients with LVNC at our institution was performed for purposes of another investigation. The process unexpectedly identified patients with LVNC and FBN1 gene mutations, as well as LVNC and Marfan syndrome. Results: Approximately 150 patients are followed in our clinic with LVNC. We screened this population and found 51 patients on medical therapy for reduced function. We retrospectively reviewed gene testing in these 51 patients, when available, and identified 5 patients (10%) with an FBN1 gene mutation. All 5 patients had a dilated LVNC phenotype and previous or current evidence of left ventricular dysfunction. Syndrome breakdown as follows: 3 with Marfan, 1 with Shprintzen-Goldberg, and 1 with no identifiable syndrome. Dilated cardiomyopathy/LVNC gene testing was performed in 3 patients; 2 had disease causing myosin heavy chain 7 gene defects and 1 had no defects. Conclusions: The role of FBN1 in the human myocardium is not completely understood but it is expressed in the developing fetal heart and is a component of the myocardial extracellular matrix. Although causation has not been proven by our report, it certainly raises interest in a mechanistic relationship between LVNC and FBN1 given the increased prevalence of Marfan syndrome and probable increased prevalence of FBN1 gene mutations in this cohort of LVNC patients in light of FBN1.