Background: Fabry disease is an X-linked disorder resulting from a deficiency of the lysosomal enzyme alpha-galactosidase A(alpha-Gal A). Renal insufficiency is a very important manifestation and affects the prognosis of patients. Recently, a renal variant type that is characterized by low plasma alpha-Gal A activity and a milder phenotype, but which progresses to end-stage renal failure, has been reported. In this study, we clarified the incidence of this atypical variant of Fabry disease in hemodialysis patients.
Methods: We measured plasma alpha-Gal A activity in 450 male dialysis patients who had never been diagnosed with Fabry disease.
Results: The mean of the alpha-Gal A activity of the patients was 9.75 +/- 3.20 nmol/h/ml, while the controls with classical Fabry (n = 3) were 0.52-1.04 nmol/h/ml. Among the patients, one patient was found to exhibit low alpha-Gal A activity in plasma (3.18 nmol/h/ml) and in leukocytes (0.639 nmol/h/mg). This patient was a 43-year-old Japanese man who had been on regular dialysis since the age of 23. He did not present typical clinical signs of classical Fabry, such as acroparesthesias or hypohidrosis, but did present renal insufficiency and severe left ventricular hypertrophy which had developed only recently, suggesting a variant form of Fabry disease. Sequencing of the DNA of this patient revealed a deletion of a single amino acid of valine in 10252.
Conclusions: A case of an atypical variant of Fabry among 450 male dialysis patients (0.22%) was found in the survey. This indicates the potential for undiagnosed Fabry disease among dialysis patients. The results of this study indicate the significance of screening for Fabry disease among male dialysis patients.