Mutation analysis and characterization of alternative splice variants of the Wilson disease gene ATP7B.

UNLABELLED: Wilson disease is a copper metabolism disorder caused by mutations in ATP7B, a copper-transporting adenosine triphosphatase. A molecular diagnosis was performed on 135 patients with Wilson disease in Taiwan. We identified 36 different mutations, eight of which were novel: five missense mutations (Ser986Phe, Ile1348Asn, Gly1355Asp, Met1392Lys, and Ala1445Pro), one deletion (2810delT) in the coding region, and two nucleotide substitutions (-133A→C and -215A→T) in the promoter region. These mutations were not observed in 100 control subjects and reduced the activity of the mutated protein by at least 50% when compared with wild-type ATP7B. In addition to exon 8, our data indicate another mutation hotspot in exon 12 where 9.62% of all mutations occurred. An alternative splice variant of ATP7B lacking exon 12 was observed in one patient who had a homozygous 2810delT mutation and very mild clinical symptoms. Clinical examination and functional characterization of alternative splice variants of ATP7B lacking exon 12 showed that they retained 80% of their biological activity. The 2810delT mutation increased the expression of these variants, which may have explained the mild symptoms in the patient with the 2810delT mutation. We also discovered that treating liver cancer cells with a Na(+)/H(+) exchanger inhibitor, 5-(N-ethyl-N-isopropyl)-amiloride, significantly enhanced the expression of the alternative splice variant of ATP7B lacking exon 12. CONCLUSION: This study suggests a novel therapeutic strategy for patients with mutations in exon 12.

Association of XPD polymorphisms with prostate cancer in Taiwanese patients.

BACKGROUND: The DNA repair gene XPD, an important caretaker of the overall genome stability, is thought to play a major role in the development of human malignancy. Polymorphic variants of XPD, at codon 312, 751, and other sites, have been associated with cancer susceptibility, but few studies have investigated their effect on prostate cancer risk. PATIENTS AND METHODS: In this hospital-based case-control study, the association of XPD codon 312, 751 and promoter-114 polymorphisms with prostate cancer risk in a Taiwanese population were investigated. In total, 123 patients with prostate cancer and 479 healthy controls recruited from the China Medical Hospital in Central Taiwan were genotyped. RESULTS: We found a significant difference in the frequency of the XPD codon 312 genotype, but not the XPD codon 751 or promoter-114 genotypes, between the prostate cancer and control groups. Those who had GIA or A/A at XPD codon 312 showed a 1.81-fold (95% confidence interval=1.21-2.69) increased risk of prostate cancer compared to those with GIG. As for XPD codon 312 or promoter-114, there was no difference in distribution between the prostate cancer and control groups. CONCLUSION: Our findings suggest that the heterozygous and homozygous A allele of the XPD codon 312 may be associated with the development of prostate cancer and may be a useful marker for primary prevention and anticancer intervention.

Association of p53 and p21(CDKN1A/WAF1/CIP1) polymorphisms with oral cancer in Taiwan patients.

BACKGROUND: The tumor suppressor gene p53 and its downstream effector p21(CDKN1A/WAF1/CIP1) are thought to play major roles in the development of human malignancy. Polymorphic variants of p53, at codon 72, and CDKN1A, at codon 31, have been associated with cancer susceptibility, but few studies have investigated their effect on oral cancer risk. MATERIALS AND METHODS: In this hospital-based case-control study, the association of p53 codon 72 and CDKN1A codon 31 polymorphisms with oral cancer risk in a Taiwanese population were investigated. In total, 137 patients with oral cancer and 105 age-matched controls recruited from the Chinese Medical Hospital in Central Taiwan were genotyped. RESULTS: We found a significant difference in the frequency of the p53 genotype, but not the CDKN1A genotype, between the oral cancer and control groups. Those who had Arg/Arg at p53 codon 72 showed a 2.68-fold (95% confidence interval = 1.19-6.01) increased risk of oral cancer compared to those with Pro/Pro. The distribution of the combination of p53 codon 72 and CDKN1A codon 31 was different in the oral cancer and control groups. The percentages of three subgroups with the p53 GG homozygote were all higher in the oral cancer group, and the risky double homozygote, p53/CDKN1A GG/CC form, was almost 9-fold higher than the control group. CONCLUSION: Our findings suggest that the homozygous Arg allele of the p53 codon 72 may be associated with the development of oral cancer and be a useful marker for primary prevention and anticancer intervention.

Mutation analysis of Taiwanese Wilson disease patients.

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.

Mutation analysis of Gaucher disease patients in Taiwan: high prevalence of the RecNciI and L444P mutations.

Gaucher disease, the most prevalent lysosomal storage disease characterized by a remarkable degree of clinical variability, results from deleterious mutations in the beta-glucosidase gene. Although >200 mutations in the gene for human beta-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.

The cuttable C-related genotype and allele for the E-cadherin 3-UTR Pml I polymorphism are associated with higher susceptibility to endometriosis

Epithelial cadherin (E-cadherin; CDH1) may influence pericellular proteolysis and intracellular signal transduction, which plays an essential part of tumor invasion. In our study we investigated the correlation between CDH1 gene polymorphism and endometriosis in two groups of pre-menopausal Taiwanese women, group 1 (n = 150) consisting of women with severe stage IV endometriosis and group 2 (n = 159) of women with no endometriosis. The polymerase chain reaction (PCR) was used to identify the cuttable (C) and uncuttable (T) polymorphism of the CDH1-Pml I gene (rs1801026) located on the 3-untranslated region (3-UTR) of chromosome 16 and compare the genotypes and allelic frequencies of this gene in both groups. We found that the genotype and allele distributions of the CDH1-Pml I C/T polymorphism were significantly different in both groups. In group 1 the CDH1*C frequency was 47.7% and the T frequency 52.3%, while the CC homozygote frequency was 6.7%, the TT homozygote 11.3% and the CT heterozygote 82%. In group 2 the CDH1*C frequency was 17% and the T frequency 83%, while the CC frequency was 0.6%, the TT 66.1% and the CT 33.3%. These data indicate that the CDH1 gene polymorphism may be associated with the development of severe endometriosis and that the CDH1 gene C allele is related to higher susceptibility to endometriosis

Tumor necrosis factor alpha, CYP 17, urokinase, and interleukin 10 gene polymorphisms in postmenopausal women: correlation to bone mineral density and susceptibility to osteoporosis.

OBJECTIVE: Osteoporosis is a common disorder with a strong genetic component. We investigated the correlations between bone mineral density (BMD) and four gene polymorphisms (-308G>A tumor necrosis factor alpha (TNF-alpha), -34T>C CYP 17, *141T>C urokinase, and -627C>A interleukin 10 (IL-10) promoter), and their relationship to osteoporosis in postmenopausal women. STUDY DESIGN: These polymorphisms were determined using polymerase chain reaction (PCR) followed by restriction fragment length polymorphism (RFLP) analysis. BMD of the lumbar spine and proximal femur were measured using dual-energy X-ray absorptiometry. RESULTS: The prevalence of each genotype was as follows: (1) 79.3% A/A, 16.6% A/G, and 4.1% G/G in -308G>A TNF-alpha; (2) 18.9% T/T, 52.1% T/C, and 29% C/C in -34T>C CYP 17; (3) 86.4% C/C and 13.6% C/T in *141T>C urokinase; (4) 46.2% A/A, 45% A/C, and 8.8% C/C in -627C>A IL-10 promoter. Subjects with genotype C/C in -627C>A IL-10 promoter had lower BMD values and a significantly greater risk for osteoporosis (OR 8.1, 95% CI 1.5-42.8) at the lumbar spine compared with subjects with genotype A/C in -627C>A IL-10 promoter, after adjustment for potential confounders. CONCLUSION: The RsaI IL-10 promoter gene polymorphism is associated with reduced BMD and predisposes women to osteoporosis at the lumbar spine.

Nonassociation of interleukin 4 intron 3 and 590 promoter polymorphisms with bronchopulmonary dysplasia for ventilated preterm infants.

Interleukin 4 (IL-4) stimulates and amplifies the inflammatory response, stimulates collagen synthesis in fibroblasts, promotes the progression to fibrosis and has been shown to inhibit the production of several inflammatory cytokines in the development of bronchopulmonary dysplasia (BPD) and airway hyperreactivity. We aimed to investigate whether IL-4 polymorphisms in ventilated preterm infants were associated with BPD. BPD was defined as infants who remained dependent on active respiratory support or oxygen supplementation at 36 weeks postconceptional age. A case-control study of 224 preterm infants (<30 weeks) who had respiratory distress syndrome and needed intermittent mandatory ventilation (IMV) were undertaken between January 1999 and December 2003. The typing of each genetic polymorphism was performed by polymerase-chain-reaction-based restriction analysis. Genotype distribution and allelic frequencies were compared between ventilated preterm infants who developed BPD and those who did not and the duration of IMV. The demography of these ventilated BPD and non-BPD preterm infants was not different. We observed no significant differences in genotype distribution or allelic frequency of the IL-4 intron 3 or IL-4 promoter polymorphisms between ventilated preterm infants who developed BPD and who did not. There was no significant association of the genotype or allelic frequency of IL-4 polymorphism with duration of IMV. We conclude that neither IL-4 intron 3 nor the 590 promoter polymorphism is a useful marker for predicting the susceptibility to BPD in ventilated Taiwanese preterm infants.

No association between TAP1 DpnII polymorphism and bronchopulmonary dysplasia.

The possibility that a family history of asthma may have a role in susceptibility to bronchopulmonary dysplasia (BPD) had been raised in several reports, and there was evidence of a strong association between transporter associated with antigen processing (TAP1) polymorphism and asthma in Taiwanese population. To test whether TAP polymorphism has a role in the BPD, we investigated the association between TAP1 polymorphism and BPD by analyzing the results of genotype distribution. The study included 224 ventilated preterm infants (<30 weeks) who had respiratory distress syndrome (RDS) and needed intermittent mandatory ventilation (IMV) during Jan. 1999 to July 2003. The typing of TAP1 polymorphism was performed by polymerase chain reaction (PCR)-based restriction analysis. The demography between two groups of these ventilated preterm infants was not different. We observed no significant differences in genotype distribution or allele frequency of the TAPI polymorphisms between BPD and their respective control infants. There was also no significant difference in genotype distribution of the TAP1 polymorphism with duration of IMV. Therefor, we conclude that TAP1 polymorphism is not a useful marker for predicting the susceptibility or severity to BPD for Taiwanese.

Angiotensin I-converting enzyme ACE 2350*G and ACE-240*T-related genotypes and alleles are associated with higher susceptibility to endometriosis.

Endometriosis displays features similar to malignancy, ranging from neovascularization to local invasion and aggressive spread to distant organs. The altered vascular-related genes might be related to the development of endometriosis. This study investigates whether angiotensin I-converting enzyme (ACE) *A2350G and A-240T gene polymorphisms could be used as markers of susceptibility in endometriosis. Women were divided into two groups: (1) endometriosis group (n=150) and (2) non-endometriosis group (n=159). Genomic DNA was obtained from peripheral leukocytes. ACE A2350G and A-240T gene polymorphisms were amplified by PCR and detected after restriction enzyme digestion with BstUI and XbaI. Genotypes and allelic frequencies in both groups were compared. We observed that genotype distribution and allele frequency of ACE 2350 and ACE-240 gene polymorphisms in both groups were significantly different. Proportions of ACE 2350*A homozygote/heterozygote/G homozygote in both groups were: (1) 66.7/29.3/4% and (2) 96.2/3.1/0.7%. Proportions of ACE-240*A homozygote/heterozygote/T homozygote in both groups were: (1) 43.3/46/10.7% and (2) 62.9/35.8/1.3%. We concluded that ACE 2350*G and ACE-240*T-related genotypes and alleles are associated with higher susceptibility to endometriosis. ACE A2350G and A-240T gene polymorphisms might be associated with endometriosis development.

No association of urokinase gene 3'-UTR polymorphism with bronchopulmonary dysplasia for ventilated preterm infants.

Pathological findings pertaining to bronchopulmonary dysplasia (BPD) are consistent with a process of prolonged lung inflammation and impaired healing. The balance of the competing activities of coagulation and fibrinolysis may contribute to the premature lung's response to acute injury. We investigated the association of the urokinase gene polymorphism with BPD in ventilated preterm infants whose gestational age was below 30 weeks. BPD is defined as infants remaining dependent upon active respiratory support and/or oxygen supplementation and featuring characteristic radiographic changes in the lung fields on the 28th postnatal day (BPD-28d) and at a corrected age of 36 weeks of gestation (BPD-36w). Two hundred and four ventilated preterm infants were enrolled in the study. The typing of each specific genotype polymorphism was performed by polymerase chain reaction (PCR) and restriction analysis. Perinatal risk factors for BPD, genotype distribution, and allelic frequencies were compared between infants suffering from BPD (28-d), BPD (36-w) and their respective ventilated preterm infants who did not develop BPD infants. The genotype proportions of the urokinase 3'-UTR polymorphism for BPD (28-d), BPD (36-w) and their respective ventilated preterm infants who did not develop BPD did not differ significantly. There was no difference in allelic frequency for the urokinase 3'-UTR polymorphism between BPD (28-d), BPD (36-w) and their respective ventilated preterm infants who did not develop BPD infants. We concluded that urokinase gene 3'-UTR C/T polymorphism is not a suitable marker for predicting susceptibility and severity to BPD for preterm infants of Taiwanese.