A 21-year-old man presented to the nephrology clinic with burning pain in his arms and legs. He had been suffering with this pain since 10 years, however, he only decided to visit the clinic after he noticed foamy urine for a month.
Physical examination of the patient included a neurologic examination which was unremarkable. Although, an analysis of the urine revealed proteinuria. The serum creatinine level of the patient was 81 μmol per per litre (0.9 mg per decilitre) (reference range, 62 to 106 μmol per litre [0.7 to 1.2 mg per decilitre]), and the urinary protein excretion was 1335 mg per 24 hours (reference range, 0 to 140).
For further evaluation, the kidneys were biopsied which showed a presence of vacuoles within the podocytes. In addition, electron microscopy of the kidneys revealed layered membrane structures, resembling zebras (also known as zebra bodies), within enlarged lysosomes in the podocytes. The findings were consistent with the diagnosis of Fabry’s disease, which was further confirmed when a mutation in the gene encoding alpha-galactosidase A (GLA) was detected.
Fabry’s disease
Fabry’s disease is an X-linked lysosomal storage disorder that is caused by mutations, resulting in absent or low activity of alpha-galactosidase A. As a result of this deficiency, there is an accumulation of globotriaosylceramide in cells which results in the formation of the characteristic zebra bodies.
Treatment for Fabry’s disease includes enzyme replacement therapy, however, this treatment was not available in the region the patient was living in. Therefore, treatment was initiated with carbamezapine, for managing pain. The pain was well controlled after at a 10-month follow-up, creatinine level was normal, however, proteinuria had not subsided.
References
Huang, X., & Zhang, R. (2020). Zebra Bodies in the Kidney. The New England Journal of Medicine, 383(1), e2-e2.
