Fabry disease

Fabry disease is a rare X-linked lysosomal storage disorder in which deficiency of alpha-galactosidase A leads to accumulation of substrate, mostly globotriaosylceramide (Gb3), which causes a progressive, multiorgan disease affecting predominantly the kidneys, skin, heart, and nervous system. Painful peripheral (‘acral’) neuropathy is characteristic. Proteinuria and estimated glomerular filtration rate (eGFR) are strongly associated with risk of progression, but this may be reduced by treatment with angiotensin-converting enzyme inhibitors as well as by enzyme replacement therapy (ERT). ERT was approved in 2001; it improves pain and other neuropathic symptoms, and well-being, and has been proven to clear deposits of Gb3 from tissues, at variable speeds. There is limited randomized controlled trial data but protective effects have been proven for renal outcomes, death, and better outcomes in some other organ systems. Renal function may be protected if ERT is commenced before there is heavy proteinuria or substantial loss of GFR. It is recommended to start ERT as soon as the diagnosis is made in those with very low or absent enzyme. For those with intermediate levels it is recommended to commence treatment only when signs or symptoms appear. Proteinuria and eGFR give most information from a renal point of view, but renal biopsy is also useful for confirming the renal diagnosis and staging the disease as well as monitoring progress in selected cases. Management should include regular screening for complications including myocardial and neurological assessments. It is likely that registries will show progressive rises in median survival with this condition.