Association of ANK2 Mutation and Massive Myocardial Calcification: A Case Report

Abstract

<h3>Introduction</h3> A 35-year-old man with no prior history of cardiovascular diseases was admitted with progressive exertional chest discomfort. Physical examination revealed irregular heart rhythm and an ejection murmur at the aortic area. EKG showed atrial fibrillation, and chest X-ray, calcification within the cardiac silhouette. Laboratory tests were all within normal ranges, including serological and inflammatory tests. <h3>Case Report</h3> An echocardiogram demonstrated diffuse myocardium calcification and intense mitral- aortic fibrocalcification, causing severe stenosis and moderate regurgitation, with a dilated left ventricle (LV) and moderate systolic dysfunction, akinesia of the inferolateral walls and hypokinesia of the anterior walls. A 128-row multidetector CT showed massive calcification affecting the aortic and mitral valves, the right ventricle, the left atrium wall and all the segments of the LV, preserving only the basal septum. Cardiovascular magnetic resonance imaging 1.5T revealed diffuse myocardial thickening, matching the areas seen on CT (figure). These areas were hypointense on the SSFP cine images and on T1- and T2-weighted images and had no late gadolinium enhancement (LGE). However, there was LGE in the underlying myocardium, in a non-ischemic distribution. Pericardium and coronary arteries were preserved. Genetic analysis identified a rare heterozygous variant of uncertain significance, c.10702C>T(p.Arg3568Trp), in ANK2 gene. <h3>Summary</h3> Ankyrin-B, also known as Ankyrin-2, is encoded by the ANK2 gene, which plays critical roles in the localization and stabilization of ion transporters and ion channels in cardiomyocytes. The Ankyrin-B syndrome has been associated to long QT syndrome and torsades depointes, but there are no reports of myocardial calcification. The patient was found to be a candidate for cardiac transplantation and is currently on the waiting list.