Mutation identification and characterization of a Taiwanese patient with fucosidosis.
Fucosidosis is a rare lysosomal storage disease caused by a defect of the alpha-L: -fucosidase (FUCA1) gene. Worldwide 26 mutations underlying the disease have been reported. By direct DNA sequencing of exons and flanking introns, homozygous Y126X mutation and Q281R polymorphism were found in a Taiwanese patient with fucosidosis. Upon expressing in COS-7 cells, 97.4% of alpha-L: -fucosidase activity compared with that of the wild-type construct was observed in the cDNA containing Q281R polymorphism. Western blot analysis revealed a 58-kDa precursor and 56-kDa mature forms for cells transfected with wild-type and Q281R enzymes. Using the fluorogenic substrate, the Michaelis constants and maximal velocities of both enzymes were very similar. While no appreciable enzyme activity (0.0%) was observed with Y126X mutation, no apparent decrease in FUCA1 mRNA level was seen with Y126X mutation. The expressed truncated Y126X protein was unstable and largely degraded. The delineation of the molecular defect could serve to complement future prenatal diagnosis for this family when necessary.
Lin
Shuan-Pei
SP
Division of Genetics and Metabolism, Departments of Pediatrics and Medical Research, Mackay Memorial Hospital, Taipei, Taiwan.|Mackay Medicine, Nursing and Management College, Taipei, Taiwan.|Department of Infant and Child Care, National Taipei College of Nursing, Taipei, Taiwan.
Chang
Jui-Hung
JH
Department of Life Science, National Taiwan Normal University, 88 Ting-Chow Road, Section 4, Taipei, 116, Taiwan.
de la Cadena
Maria Paez
MP
Department of Biochemistry, Genetics and Immunology, Faculty of Sciences, University of Vigo, Vigo, Spain.
Chang
Ting-Fang
TF
Department of Life Science, National Taiwan Normal University, 88 Ting-Chow Road, Section 4, Taipei, 116, Taiwan.
Lee-Chen
Guey-Jen
GJ
Department of Life Science, National Taiwan Normal University, 88 Ting-Chow Road, Section 4, Taipei, 116, Taiwan. t43019@ntnu.edu.tw.
D000328:Adult; D005260:Female; D005645:Fucosidosis / Q000235:genetics*; D006801:Humans; D009154:Mutation; D011110:Polymorphism, Genetic; D013624:Taiwan; D005644:alpha-L-Fucosidase / Q000235:genetics*
D005644:alpha-L-Fucosidase