Increased frequency of congenital heart defects in Menkes disease

Abstract

ATP7A is a copper-transporting ATPase critical for central and peripheral nervous system function. Mutations in ATP7A cause Menkes disease and occipital horn syndrome (OHS), allelic X-linked recessive conditions that feature vascular abnormalities ascribed to low activity of lysyl oxidase, a copper-dependent enzyme. From a recently created Menkes disease/OHS patient registry, we identified four of 95 patients with major congenital heart defects (4.2%), a proportion exceeding the general population prevalence (≈1%). In conjunction with mouse models of Menkes disease, OHS, and lysyl oxidase deficiency (which feature aortic aneurysms, irregular attachment between vascular endothelium and mesoderm, and other defects of embryological development) our observation suggests an important role of copper metabolism in cardiac development. Congenital heart disease may be an under-appreciated abnormality in Menkes disease, and should be considered in a broad differential diagnosis of cardiac defects found prenatally in male fetuses. Conversely, newborn infants with suspected or confirmed Menkes disease should be evaluated for heart disease by careful clinical examination and echocardiography, if indicated.

Figures

Figure 1

Echocardiographic abnormalities in Menkes disease. A series of echocardiographic images from patient #3 at age two years who underwent balloon valvuloplasty in the newborn period for severe pulmonary valve stenosis. By age two years, the right ventricle, atrium (panel A), and pulmonary artery (panel B) were massively dilated, and there was severe tricuspid valve regurgitation (panel C). Although valvular insufficiency is not uncommon following valvuloplasty, the degree of right heart dilation and dysfunction in this patient with Menkes disease was more severe, and developed more rapidly than expected.