Natural History in Fabry Disease With IVS4+919G>A Mutations

Fabry disease (FD) is a genetic condition where mutations in the GLA gene cause low activity of an important enzyme (alpha-Galactosidase A). This leads to harmful substances building up in the body. A key marker is lyso-Gb3, which can damage organs. FD commonly affects the heart, causing left ventricular hypertrophy (LVH), fibrosis, and worsening heart function over time. In East Asian populations, the exact natural progression of FD is not well understood, even though a specific mutation called IVS4+919G\>A is relatively common due to a "founder effect" seen in places like Taiwan and also in Hong Kong. People with this mutation often develop heart problems later in life, with LVH typically increasing after about age 40. Researchers use advanced heart scans to detect early disease. Cardiac MRI (CMR) native T1 mapping (without contrast) can distinguish normal heart tissue from FD-related changes. CMR measures can reflect different stages of heart damage-starting with accumulation, then inflammation and muscle thickening, and finally fibrosis and impaired function. Some women may not have clear blood test abnormalities yet can still develop ongoing heart damage. Because some MRI findings (like late gadolinium enhancement, LGE) may represent inflammation as well as fibrosis, and because heart damage can progress even before symptoms appear, non-invasive monitoring is important. Imaging methods like strain echocardiography and repeated T1 mapping can track progression, including in patients without obvious early heart thickening. Finally, since most previous studies have included fewer East Asian patients, the study aims to better define the natural history of FD in Chinese patients with the IVS4+919G\>A mutation by following them over time with regular health checks, blood and enzyme testing, kidney and heart function tests, and family/genetic mapping. The goal is to improve guidelines for screening, monitoring, and deciding when to start treatment (ERT).