A patient with Fabry disease whose first presentation was myocardial hypertrophy was initially misdiagnosed as obstructive hypertrophic cardiomyopathy. Cardiac MRI findings prompted enzyme, biomarker and long-range PCR testing, which confirmed the diagnosis, and the patient's condition stabilized on enzyme replacement therapy.
A patient with Fabry disease presenting first with myocardial hypertrophy was initially misdiagnosed as obstructive hypertrophic cardiomyopathy.
Mavacamten treatment did not relieve the patient's symptoms.
Cardiac magnetic resonance showed symmetric left ventricular hypertrophy with characteristically reduced myocardial T1 values, which pointed toward Fabry disease.
Long-range PCR detected a large-fragment deletion in the GLA gene, which confirmed the Fabry disease diagnosis.
Enzyme replacement therapy with agalsidase alfa stabilized the patient's condition.
This case report describes a patient whose heart muscle was thickened, a finding that was first taken to be a common inherited heart condition called obstructive hypertrophic cardiomyopathy. In fact, the patient had Fabry disease, a rare genetic disorder in which a missing enzyme lets fatty substances build up in tissues, including the heart. The diagnosis was missed at first because no other organs seemed affected, there was no typical family history, and a broad genetic test (whole-exome sequencing) came back falsely negative. The patient was given mavacamten, a drug for hypertrophic cardiomyopathy, but symptoms did not improve. A cardiac MRI then showed even thickening of the left ventricle with unusually low T1 values in the heart muscle, a pattern suggestive of Fabry disease. Blood tests for the enzyme and a related biomarker, together with a more targeted genetic technique (long-range PCR), found a large deletion in the GLA gene and confirmed Fabry disease. After starting enzyme replacement therapy (agalsidase alfa), the patient's condition became stable. This research suggests that Fabry disease can mimic hypertrophic cardiomyopathy, and that a negative standard genetic test does not fully rule it out. Specific MRI findings may help doctors decide when to look further. As a single case, it cannot show how often this happens or how well the treatment works in general.
Wang Y, Zhang Y, Zhao L, Wang H, Wang Y, Lyu J, et al.. (2026). [Fabry disease misdiagnosed as obstructive hypertrophic cardiomyopathy: a case report].. Zhonghua xin xue guan bing za zhi. https://doi.org/10.3760/cma.j.cn112148-20260521-00334