[A boy with Fabry disease with the onset at the age of four]

Fabry disease is an X-linked recessive lysosomal storage disorder caused by a deficiency of α-galactosidase A (GLA). Intracellular accumulation of globotriaosylceramide, the glycolipid substrate of this enzyme, leads to severe painful neuropathy with progressive renal, cardiovascular, and cerebrovascular dysfunction. Patients of severe cases die young. It has been proved that enzyme replacement therapy is a useful method to treat patients with Fabry disease. But the clinical diagnosis of the patients may often be difficult because of the lack of specific symptoms. In this study, a Chinese boy was diagnosed as Fabry disease at the age of 11 years with episodic pain for 7 years. The boy described the onset, at the age of 4 years, of episodic burning pain in the toes. Generalized aching and pain in the feet became progressive in the past two years and his hands were also affected. Divers analgesics were tried without effects. When he was admitted at the age of 11 years, none of complications was found in his heart, brain, kidneys, skin and eyes by routine laboratory examinations. Significantly decreased GLA activity of peripheral leucocytes [1.0 nmol/(h×mg protein) vs. normal control 24.5 to 86.1 nmol/(h×mg protein)] supported the diagnosis of Fabry disease. A splicing mutation IVS6+2 T>C was identified on his GLA gene. But it was not found in his mother and younger sister. The incidence of Fabry disease is not clear in Mainland China. The patients usually have insidious onset with complex and non-specific clinical manifestations. Stroke, uremia, cardiomyopathy and multiple organ dysfunctions are common at the late stage. Early diagnosis is the key point to reduce the mortality and handicap. GLA enzyme activity is important to the diagnosis of Fabry disease. The mutation analysis of GLA gene is helpful for genetic counseling.