Fabry Disease, Cardiac Variant

Fabry disease (FD) is a rare X-linked lysosomal storage disorder caused by α-galactosidase A (GLA) gene mutations leading to reduced or undetectable α galactosidase A (α-Gal A) enzyme activity, resulting in progressive accumulation of globotriaosylceramide (GL3) and its deacylated form globotriaosylsphingosine (Lyso-GL-3) in multiple organs, causing neural, renal, cardiac, dermatological, gastrointestinal and ophthalmic manifestations, even leading to life-threatening complications. Cardiovascular and cerebrovascular complications (i.e. heart failure, stroke, etc.) or end-stage renal disease even premature death can be seen in severe cases. The life expectancy of male patients is reduced by 15
20 years, while that of female patients is reduced by 6
10 years.
The exact prevalence of FD is currently unknown. Based on an estimated prevalence of 1:60,000, there are approximately 23,000 affected FD patients in China. The clinical manifestations of FD are diverse and non-specific, which may lead to misdiagnosis in patients with non-typical clinical manifestations in the absence of a family history of FD. Cardiac involvement can be recognized in up to 68% patients with FD, significantly higher than in other organs, and the positive screening rate for FD in adults with unexplained left ventricular hypertrophy (LVH)/hypertrophic cardiomyopathy was 0.9%.
Cardiovascular disease is the leading cause of death in patients with FD cardiomyopathy (40.2%). The 2020 Expert Consensus Document on the Management of Cardiovascular Manifestations of Fabry Disease recommends early screening in patients with suspected LVH for early diagnosis. Therefore, strengthened screening strategy in high-risk patients with LVH will improve the diagnosis and treatment of FD in China.

Better methods for early detection of cardiac involvement in Fabry disease are needed to inform clinical management decisions that can help prevent or slow the progression of cardiac complications. In the Molecular Imaging of Inflammation in Fabry Disease of the Heart study, the investigators will test the use of 68Ga-DOTATATE PET/MRI for identifying myocardial inflammation in patients with Fabry disease.

Patients and healthy controls will undergo cardiopulmonary exercises and testing of the muscles strength to gain additional understanding of exercise intolerance as Fabry disease (FD) manifestation. An additional needle muscle biopsy may be performed. Tissue analysis from this biopsy will include evaluation of the lipidomics profile and mitochondrial function. Results of the tests and any potential exercise intolerance will be compared against healthy, age-, sex- and BMI-matched volunteers. The hypothesis is that patients with FD will have reduced exercise capacity due to changes in skeletal and cardiac muscle energy metabolism.