Early diagnosis and treatment may prevent the development of complications in an adult patient with glycogen storage disease type Ia.

Type Iota(a) glycogen storage disease (GSD Iota(a)) is caused by the deficiency of glucose-6-phosphatase activity, which results in metabolic disorder and organ failure, including renal failure. GSD Iota(a) patients are generally diagnosed at a median age of 6 months. However, we report a 20-year-old Japanese female with newly diagnosed GSD Iota(a) . The renal disorder of GSD Iota(a) is considered to be produced by glomerular hyperfiltration, TGF-beta expression which is induced by renin-angiotensin-aldosterone system (RAS) and uric acid, and the increase in both small dense LDL and modified LDL which is characteristic of GSD Iota(a) as well as hypertriglyceridemia. With the administration of intensive therapies, including angiotensin type 1-receptor blocker and some lipid lowering drugs, along with traditional dietary therapy, daily proteinuria of the patient improved from 2.1 g to 0.78 g. Although the patients of GSD Iota(a) should receive an early and accurate diagnosis and effective therapies before the age of 1 year, the combination of traditional dietary therapies and intensive therapies may have therapeutic potential for the complications of adult patients. In this report, we describe the management of renal disease and the characteristic features of this metabolic disorder.