Mucopolysaccharidosis I presenting with endocardial fibroelastosis of infancy
M. J. Stephan, E. L. Stevens Jr, R. J. Wenstrup, C. R. Greenberg, H. L. Gritter, G. F. Hodges and B. Guller
Department of Pediatrics, Madigan Army Medical Center, Tacoma, Wash 98431.
We describe two female infants with Hurler syndrome (mucopolysaccharidosis
I) whose deaths are attributed to cardiac failure with associated,
autopsy-confirmed endocardial fibroelastosis. One infant had confirmed
alpha-L-iduronidase deficiency in cultured dermal fibroblasts, and the
other infant had histologic evidence of tissue mucopolysaccharide
accumulation at autopsy and a sibling with confirmed alpha-L-iduronidase
deficiency and the Hurler syndrome phenotype. Clear cells ("Hurler" cells)
were identified within the myocardium and endocardium of both infants. We
propose that the ventricular mural accumulation of mucopolysaccharides
induced extensive proliferation of elastic or collagen fibers within the
endocardium. Cardiac failure may precede recognition of clinical and
roentgenographic features of Hurler syndrome. Our findings and a literature
review suggest that certain heritable storage disorders, including
mucopolysaccharidosis I, should be considered when infants have clinical
electrocardiographic and echocardiographic findings consistent with
endocardial fibroelastosis or have autopsy-documented endocardial
fibroelastosis.
