Association of Renal Ectopia With Fabry's Disease in 3 Patients

Abstract

Fabry's disease is a rare, inherited lysosomal storage disorder characterized by decreased activity of the lysosomal hydrolase alpha-galactosidase A and impaired degradation of globotriaosylceramide, which accumulates in the lysosomes of virtually every cell in the body. Kidney damage is a prominent feature of the disease but to our knowledge renal ectopia as a comorbidity has not been previously reported. We present clinical and genetic features in 2 female and 1 male patient with Fabry's disease and renal ectopia. The diagnosis of Fabry's disease was made by measuring alpha-galactosidase A activity in blood leukocytes and by mutational analysis of the alpha-galactosidase A gene. The anatomical location of the kidneys was defined by native and single bolus 3-phase coronal computerized tomography angiography. To determine the possible genetic association of Fabry's disease and renal ectopia we performed a genetic analysis of informative, closely linked microsatellite markers surrounding the gene. All patients carried the c.469C>T mutation in the alpha-galactosidase A gene, causing premature stop codon (Glu157X). In all 3 patients downward dislocation of the right kidney (pelvic kidney) was found in association with double renal arteries. We noted that a haplotype telomeric to the alpha-galactosidase A gene cosegregated with renal ectopia in 3 family members, suggesting the existence of a gene for X-linked renal ectopia in the region of DXS1001-DXS1073. To our knowledge this is the first report of an association of renal ectopia with Fabry's disease.