%0 Journal Article
%T Myocardial ischemia in the absence of epicardial coronary artery disease in Friedreich's ataxia
%A Subha V Raman
%A Jennifer A Dickerson
%A Roula Al-Dahhak
%J Journal of Cardiovascular Magnetic Resonance
%D 2008
%I BioMed Central
%R 10.1186/1532-429x-10-15
%X This report describes myocardial perfusion reserve abnormality in Freidreich's ataxia (FA), a heritable disorder whose major manifestations are neurological and myocardial disease. In more than 90% of cases, this autosomal recessive condition results from excess of DNA triplet repeats (GAA) in the first intron at the end of exon 1 leading to suppression of FRDA (frataxin) gene expression. Around 5% of patients have a point mutation in the frataxin gene; both forms result in a deficiency of the protein frataxin that is located in the inner mitochondrial membrane[1]. Frataxin deficiency results in mitochondrial iron accumulation in neurons, cardiomyocytes and other cell types. Historically, diagnosis of cardiac involvement in FA has relied on nonspecific electrocardiographic abnormalities and imaging-based detection of ventricular hypertrophy[2], neither of which yields significant insight into mechanisms of disease that would allow development of targeted therapies. We sought to test the utility of cardiac magnetic resonance (CMR) in identifying microvascular abnormalities in FA, a previously unexplored target for cardiotherapeutic intervention in this disorder.A 26 year-old nonsmoking Middle Eastern woman presented for evaluation of exertional chest pain and shortness of breath. The past medical history was notable for genotype-proven Friedreich's ataxia (FA) diagnosed at age 19 that had produced ambulatory limitation with frequent falls due to her ataxia. Genotyping showed 846GAA repeats (normal ¡Ü 33) consistent with FA. Family history revealed extensive affected members and carriers (Figure 1). Further, a nephew with FA had died suddenly at age 21 of presumed cardiac etiology. There was no history of diabetes or hypertension, though serologic examination revealed elevated low-density lipoprotein level (199 mg/dL); serum triglyceride level was within normal limits (57 mg/dL). Cardiovascular physical examination was unremarkable. To evaluate for possible cardiomyopa
%U http://jcmr-online.com/content/10/1/15