1106 Twins with uncertain significant mutations, slightly different cardiomyopathies and different oucmes

Abstract

Abstract Dilated cardiomyopathy (DCM) is defined as left ventricle (LV) dilatation and dysfunction in the absence of abnormal loading conditions or coronary artery disease enough to cause global systolic impairment. It is the leading cause of heart failure and sudden cardiac death, and even in the early stages of life 5,7/1.000.000 children are diagnosed each year. Lately, genetic screening has revealed that 30-50% of the cases have a familial origin, with a high genetic heterogeneity. We present the case of a 4-month-old boy (case A) referred to our Hospital with high suspicion of dilated cardiomyopathy. He had a twin brother, pregnancy went without complications, pre-birth ultrasound and blood tests were completely normal and a caesarean birth was planned at 37 weeks of pregnancy. He also has an older sibling with no medical history. Our patient was the first to be born and was admitted to the neonatal-ICU due to tachypnea, labored breathing and desaturation. In the physical exam a 5cm hepatomegaly was detected and on the X-Ray a cardiomegaly and enlarged mediastinum were confirmed. ECG showed no electrical abnormalities besides vague repolarization changes. A TTE was done, showing remarkable left cavities enlargement with severe left ventricle dysfunction and moderate mitral regurgitation, comprising the right filling and therefore the right cardiac output. These findings were confirmed by MRI, not detecting enhancement patterns compatible with myocarditis. A genetic test was performed in the index case detecting the presence of a mutation in the desmin gene (Des C.568 + 10c) and the myosin heavy chain 7 gene (Myh7p - glu883Ala) both associated either with dilated and noncompaction cardyomiopathies. Due to the elevated chances of a familiar-DCM his twin brother was admitted to study (case B), with no symptoms or clinical signs besides an isolated bronchitis episode. The clinical examination and EKG were normal, detecting in the TTE a slightly dilated left ventricle with non-compactation morphology in the LV lateral wall, but no left ventricle dysfunction. Also, a TTE was performed in their father with similar findings: mild LV dilatation with minor systolic disfunction and uncertain non-compactation morphology in the LVl apex. Abnormalities of specific genes are now known to be responsible for different types of congenital heart diseases with important implications in genetic counseling. We want to emphasize the different manifestation of a single mutation on different members of a family, even in this two twin-brothers that, under the same probable conditions during preganancy, had slightly different cardyomyopathies but very different severity, and probable mid to long term prognosis. Abstract 1106 Figure.