Fabry disease, a rare genetic disorder affecting multiple organs, has understudied correlations among enzyme activity, genotype, and clinical manifestations in patients of different sexes with classical and late-onset phenotypes. In this study, clinical data, α-Gal A activity, and GLA gene test results of 311 patients, who were categorized by classical and late-onset phenotypes, ⩽5% and > 5% of the normal mean value of enzyme activity, and truncated and nontruncated mutation groups, were collected. The common clinical manifestations of Fabry disease included acroparesthesia, hypohidrosis/anhidrosis, neuropsychiatric system, and renal and cardiovascular involvement. Multiorgan involvement was higher in males and classical phenotype patients. In both sexes, classical patients commonly presented with acroparesthesia and multiorgan involvement, whereas late-onset patients showed renal, neuropsychiatric, and cardiovascular involvement. Male and classical patients had lower enzyme activity than female and late-onset patients, respectively. Classical males with enzyme activity of ⩽5% of the normal mean level showed higher multiorgan involvement frequency than those with enzyme activity of > 5%, whereas no significant difference was observed among females. Ninety-five gene mutation sites were detected, with significant phenotype heterogeneity in patients with the same mutation. No significant difference in enzyme activity or clinical manifestations was observed between truncated and nontruncated mutations. Overall, male patients with Fabry disease, regardless of classical or late-onset phenotype, have a higher frequency of multiple-organ involvement and lower α-Gal A activity than female patients. α-Gal A activity was closely correlated with clinical symptoms in males but weakly correlated with clinical manifestations in females. The clinical manifestations of patients with the same mutation are heterogeneous, and the correlation between gene mutation and enzyme activity or clinical manifestation is weak.
Adolescent ; Adult ; Aged ; Female ; Humans ; Male ; Middle Aged ; Young Adult ; Age of Onset ; alpha-Galactosidase/metabolism* ; China ; Fabry Disease/enzymology* ; Genotype ; Mutation ; Phenotype ; Sex Factors ; East Asian People/genetics*

No abstract available.
Biopsy ; DNA Mutational Analysis ; *Diagnostic Errors ; Enzyme Replacement Therapy ; Fabry Disease/complications/*diagnosis/enzymology/genetics ; Genetic Predisposition to Disease ; Glomerulonephritis, IGA/diagnosis/etiology ; Humans ; Male ; Middle Aged ; Mutation ; Phenotype ; Predictive Value of Tests ; Purpura, Schoenlein-Henoch/*diagnosis ; alpha-Galactosidase/genetics/therapeutic use

Fabry disease is an X-linked inborn error of glycosphingolipid catabolism that results from mutations in the gene encoding the alpha-galactosidase A (GLA) enzyme. We have identified 15 distinct mutations in the GLA gene in 13 unrelated patients with classic Fabry disease and 2 unrelated patients with atypical Fabry disease. Two of the identified mutations were novel (i.e., the D231G missense mutation and the L268delfsX1 deletion mutation). This study evaluated the effects of the chemical chaperones 1-deoxygalactonojirimycin (DGJ) on the function of GLA in vitro, in cells containing missense mutations in the GLA gene. Nine missense and a nonsense mutations, including one novel mutation were cloned into mammalian expression vectors. After transient expression in COS-7 cells, GLA enzyme activity and protein expression were analyzed using fluorescence spectrophotometry and Western blot analysis, respectively. DGJ enhanced GLA enzyme activity in the M42V, I91T, R112C and F113L mutants. Interestingly, the I91T and F113L mutations are associated with the atypical form of Fabry disease. However, DGJ treatment did not have any significant effect on the GLA enzyme activity and protein expression of other mutants, including C142W, D231G, D266N, and S297F. Of note, GLA enzyme activity was not detected in the novel mutant (i.e., D231G), although protein expression was similar to the wild type. In the absence of DGJ, the E66Q mutant had wild-type levels of GLA protein expression and approximately 40% GLA activity, indicating that E66Q is either a mild mutation or a functional single nucleotide polymorphism (SNP). Thus, the results of this study suggest that the chemical chaperone DGJ enhances GLA enzyme activity and protein expression in milder mutations associated with the atypical form of Fabry disease.
1-Deoxynojirimycin/*analogs & derivatives/metabolism ; Adolescent ; Adult ; Animals ; Asian Continental Ancestry Group/*genetics ; COS Cells ; Cercopithecus aethiops ; Fabry Disease/*enzymology/genetics ; Gene Expression ; Humans ; Male ; Middle Aged ; Mutation ; Young Adult ; alpha-Galactosidase/*genetics/*metabolism