MRI assessment of cardiomyopathy in Taiwan Chinese late-onset Fabry mutation (IVS4+919G>A)

Background Fabry disease is a rare X-linked disorder characterized by deficiency ofa-galactosidase A, leading to progressive accumulation of glycosphingolipid in various organs, including the heart. Recently, several later-onset phenotypes of Fabry disease with residual enzyme activity have been identified. In Taiwan, several recent studies pointed out a surprisingly high incidence of a later onset Fabry mutation (IVS4+919G>A) and there is a lack of information about its cardiac MR appearance in the literature. We aim to present the cardiac MR appearances of this subtype of Fabry disease and compare them with the classic type. Methods A total of 12 patients (9 males and 3 females) were enrolled in this study. They underwent endomyocardial biopsy as well as MR study from July 2013 to September 2014 and were proved to be Fabry mutation (IVS4 +919G>A). We recorded the location of delayed myocardial enhancement according to modified AHA 16-segment model and measured left ventricular (LV) wall thickness of each segment in short axis view at the end diastole. We categorized these patients into three groups (Group I, II, III) according to their myocardial thickness(all segments<12mm, at least one segment 12~16mm, at least one segment>16mm, respectively ). Among the all