Novel α-galactosidase A gene mutation in a Chinese Fabry disease family: A case report.

Background: Fabry disease (FD) is a rare X-linked lysosomal storage disease caused by a deficiency of the enzyme α-galactosidase A.

Case Summary: Herein, we analyzed a four-generation Chinese family. The proband is a 57-year-old woman who was diagnosed with left ventricular hypertrophy and atrial fibrillation 7 years ago. Echocardiography showed an end-diastolic diameter of the interventricular septum of 19.9 mm, left ventricular end-diastolic diameter of 63.1 mm, and moderate-to-severe mitral regurgitation. Cardiac magnetic resonance indicated an enlarged left heart and right atrium, decreased left ventricular systolic and diastolic function, a left ventricular ejection fraction of 20%, and thickening of the left ventricular septum. In March 2019, gene and enzyme activity tests confirmed the diagnosis of FD. Her son was diagnosed with FD after gene and enzyme activity assay, and was prescribed agalsidase-β for enzyme replacement therapy in July 2020. Two sisters of the proband were also diagnosed with FD by genetic testing. Both of them had a history of atrial fibrillation.

Conclusion: A novel mutation was identified in a Chinese family with FD, in which the male patient had a low level of enzyme activity, early-onset, and severe organ involvement. Comprehensive analysis of clinical phenotype genetic testing and enzyme activity testing helped in the diagnosis and treatment of this FD family.