Characterization of the Cardiac Phenotype of Friedreich's Ataxia (FRDA)

Friedreich's Ataxia - Inclusion Criteria: * Males and females, age 12 to 50 * Willing and able to provide informed consent (adolescents will need to provide assent and a parent to provide consent) * Definitive diagnosis of FRDA, based on clinical phenotype and genotype * Left ventricle ejection fraction measured by ECHO of \>35% (If results of an ECHO are not available for a potential subject, then an ECHO will first be performed and subjects with an LVEF \<35% will not be required to perform the CPET) Friedreich's Ataxia - Exclusion Criteria: * Signs and symptoms of cardiac failure * Moderate to severe atrial or ventricular arrythmias * History of angina pectoris * Implanted pacemaker and/ or defibrillator or any other device that would preclude MRI assessment * Any form of dialysis; Severe or end-stage CKD (CKD 4 or 5, eGFR \< 30 ml/min/1.73 m2) without dialysis; eGFR 30 to 40 ml/min/1.73 m2 without dialysis; Acute kidney injury (If a recent assessment is not available, then a blood test to assess kidney function will be performed prior to cardiac MRI) * Females who are pregnant * Receipt of an investigational drug within 30 days or 5 half-lives, whichever is longer, prior to screening, or active enrollment in an investigational medication or device study * Unable to undergo cardiac MRI with gadolinium contrast or claustrophobia * Clinical history or evidence of Type 1 or Type 2 Diabetes mellitus * Any condition, disorder, or abnormal laboratory test findings at screenin…