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Abstract: Wilson disease (WD) is an autosomal recessive disorder of copper metabolism, which is caused by mutation in copper-transporting ATPase (ATP7B). In the present study, we report a molecular diagnosis method to screen the WD chromosome in patients or in heterozygotic carriers in Taiwan. Exons 8, 11, 12, 13, 16, 17, and 18 of ATP7B are selected for the screening of mutations. The most common mutation, Arg778Leu or Arg778Gln, was first screened by PCR-RFLP then we combined single-stranded conformation polymorphism (SSCP) analysis followed by direct DNA sequencing on the DNA fragments with mobility shift on SSCP analysis. The diagnostic rate was compared with standard ATP7B whole gene sequencing analysis. Ten different mutations were identified among 29 WD patients; among them four were novel (Ala1168Pro, Thr1178Ala, Ala1193Pro, and Pro1273Gln). The false positive rates were tested against 100 normal individuals and listed as follows: exon 8: 5%; exon 11: 4%; exon 12: 6%; exon 13: 5%; exon 16: 5%; exon 17: 3%; exon 18: 4%. The Arg778Leu mutation exhibited the highest allelic frequency (43.1%). The detection rate of WD chromosomes is 65.52%, which is as sensitive as whole gene sequencing scanning. According to our results, WD chromosomes in Taiwan are predominantely located at exons 8, 11, 12, 13, 16, 17, and 18. The standard sequencing analysis on the entire gene is time consuming. We recommend screening these 7 exons first on those individuals who have a higher risk in having WD, before whole gene and promoter sequencing analysis in Taiwan. [Copyright &y& Elsevier]

Carboxylesterases are mainly involved in the mediation of metabolic resistance of many insects to organophosphate (OP) insecticides. Carboxylesterases underwent two divergent evolutionary events: (1) quantitative mechanism characterized by the overproduction of carboxylesterase protein; and (2) qualitative mechanism caused by changes in enzymatic properties because of mutation from glycine/alanine to aspartate at the 151 site (G/A151D) or from tryptophan to leucine at the 271 site (W271L), following the numbering of Drosophila melanogaster AChE. Qualitative mechanism has been observed in few species. However, whether this carboxylesterase mutation mechanism is prevalent in insects remains unclear. In this study, wild-type, G/A151D and W271L mutant carboxylesterases from Culex pipiens and Aphis gossypii were subjected to germline transformation and then transferred to D. melanogaster . These germlines were ubiquitously expressed as induced by tub -Gal4. In carboxylesterase activity assay, the introduced mutant carboxylesterase did not enhance the overall carboxylesterase activity of flies. This result indicated that G/A151D or W271L mutation disrupted the original activities of the enzyme. Less than 1.5-fold OP resistance was only observed in flies expressing A. gossypii mutant carboxylesterases compared with those expressing A. gossypii wild-type carboxylesterase. However, transgenic flies universally showed low resistance to OP insecticides compared with non-transgenic flies. The flies expressing A. gossypii W271L mutant esterase exhibited 1.5-fold resistance to deltamethrin, a pyrethroid insecticide compared with non-transgenic flies. The present transgenic Drosophila system potentially showed that a quantitative increase in carboxylesterases induced broader resistance of insects to insecticides than a qualitative change. [ABSTRACT FROM AUTHOR]

Abstract: Gaucher disease, the most prevalent lysosomal storage disease characterized by a remarkable degree of clinical variability, results from deleterious mutations in the β-glucosidase gene. Although >200 mutations in the gene for human β-glucosidase have been described, most genotype/phenotype studies have focused on screening for a few common mutations. In the present study, whole gene sequencing analysis was performed. We sequenced eight patients with type 1, five patients with type 2, and six patients with type 3 Gaucher disease in Taiwan. A total of 37 Gaucher chromosome were identified. The detection rate is 97%. For types 1 and 3 Gaucher disease, 1448 T > C (L444P) account for 53.5% Gaucher chromosome and the recombinant allele [1448 T > C, 1483 T > G, 1497 G > C] (RecNciI) has 25% prevalence rate among those patients. For type 2 Gaucher disease, all five patients carry L444P mutation, and RecNciI is found in two of the six patients. Because L444P is also present in the RecNciI mutation, all the patients in this study have a L444P mutation in their Gaucher chromosomes. The third most common mutation of type 1 Gaucher disease is 475 C > T (R120W). L444P homozygote and R120W/RecNciI genotypes are associated with non-neuronopathic Gaucher disease. RecNciI is related to neuronopathic disease, while R120W is represented as a mild mutation in Taiwan. The mutation profile of Gaucher disease in Taiwan is limited. Only four different alleles were identified in types 1 and 3 as well as in type 2 Gaucher disease. [Copyright &y& Elsevier]