began and found mumps genome in the tissues of over 80% of these patients. It seems undeniable that transplacental mumps infection had been in the past the major cause of EFE, and that immunization was indeed the cause of EFE having become rare. Non-infectious causes of EFE have also been studied, spurred by the opening of new avenues of genetics research. Now there are specific named genes associated with certain cardiomyopathies, some of which show the characteristic reaction of EFE. A typical example is Barth syndrome and the responsible gene, tafazzin. Developments in echocardiography, both the technology of the machines and the skill of the operators, have made it no longer necessary to see the endocardium at autopsy. EFE can now be found non-invasively by the recording of increased endocardial echos. Fetal echocardiography has shown that EFE can begin to accumulate as early as 14 weeks of gestation, and increase with incredible rapidity and even that it can be reversed if the stress can be removed early in fetal life. The North American Pediatric Cardiomyopathy Registry was founded in 2000 and has been supported since by the National Heart, Lung and Blood Institute. Because of the logic of the diagnostic tree, where EFE applies to many branches of the tree and thus cannot occupy a branch, it is not listed by the Registry as a cause but rather, "with EFE" is a modifier that can be applied to any cause. Thus, the past half-century has seen EFE evolve from a mysterious but frequently observed disease to a rare but much better understood reaction to many diseases and other stresses. See also Papillary fibroelastoma References External links Heart diseases Congenital disorders Autosomal recessive disorders X-linked recessive disorders Rare diseases