title: Infantile hypertrophic cardiomyopathy of glycogenosis type IX: isolated cardiac phosphorylase kinase deficiency.
abstract: Glycogen storage disease confined to the heart due to cardiac phosphorylase kinase deficiency causes a fatal infantile cardiomyopathy. Cardiomegaly can be detected in utero and is progressive. Electrocardiographic and echocardiographic findings are characteristic but not specific; these include large QRS complexes, short PR interval, and a hypertrophic nonobstructive pattern. Conclusive diagnosis requires biochemical analysis of myocardium, which may not be possible premortem due to the amount of tissue required. Pathologic examination of a standard cardiac biopsy can provide a presumptive diagnosis. There is no current treatment except a heart transplant. Infants succumb to heart failure and/or respiratory compromise due to pulmonary compression. This is a rare entity; only three cases have been reported to our knowledge. We report two additional cases.
authors.affiliation: Department of Pathology (D-33), University of Miami School of Medicine, P.O. Box 016960, Miami, FL 33101, USA.
authors.forename: J J
authors.initials: JJ
authors.lastname: Regalado
authors.forename: M M
authors.initials: MM
authors.lastname: Rodriguez
authors.forename: P L
authors.initials: PL
authors.lastname: Ferrer
mesh_terms: D001344:Autopsy; D002312:Cardiomyopathy, Hypertrophic / Q000151:congenital*; D017809:Fatal Outcome; D005260:Female; D006008:Glycogen Storage Disease / Q000175:diagnosis*; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D009206:Myocardium / Q000201:enzymology* / Q000473:pathology; D010764:Phosphorylase Kinase / Q000172:deficiency* / Q000378:metabolism
chemical_list: D010764:Phosphorylase Kinase