Different Phenotypes of Anderson-Fabry Disease Identified with Cardiac Magnetic Resonance Imaging in a Family with the Same Late-Onset Mutation.

BACKGROUND Cardiac magnetic resonance imaging (CMR) is the only noninvasive test capable of differentiating between hypertrophic cardiomyopathy (HCM) and late-onset Anderson-Fabry disease (AFD). The purpose of this report is to show how CMR led to diagnosis of AFD in 3 family members, 1 of whom previously was misdiagnosed with HCM, and how late-onset AFD can present with different cardiac phenotypes, even in a family with the same pathogenic mutation. CASE REPORT A 60-year-old man was referred because of evidence of left ventricular hypertrophy (LVH) on an electrocardiogram (ECG) that was performed to screen for cardiomyopathy. One of his siblings previously had been diagnosed with HCM and atrial fibrillation. The patient's ECG and echocardiographic findings were suspicious for HCM. CMR showed severe symmetrical LVH but tissue characterization sequences were highly suggestive of AFD cardiomyopathy. Enzymatic and genetic testing confirmed the diagnosis of late-onset AFD (presence of the GLA p.F113.L mutation). The brother of the index patient then was re-evaluated and also diagnosed with late-onset AFD. He was found to have the same pathogenic mutation but with a presentation of asymmetrical septal LVH. The daughter of the index patient was positive for the same mutation but did not have LVH. CONCLUSIONS The fact that patients with late-onset AFD can present with different LVH and fibrosis patterns, even in the presence of the same pathogenic mutation, underscores the importance of including AFD in the differential diagnosis of HCM. CMR is fundamental for differentiating between those 2 entities and defining the pathological phase of AFD. A correct diagnosis can have a substantial impact on patient management, and more so on thier families.