Identification of mutations in the ATP7B gene in 14 Wilson disease children: Case series.

INTRODUCTION: Wilson Disease (WD) is an autosomal recessive inherited metabolic disease caused by mutations in the ATPase copper transporting beta gene (ATP7B). WD can cause fatal neurological and hepatic disorders if not diagnosed and treated. OBJECTIVE: To analyze the disease-causing mutations of 14 Chinese WD children, 11 of whom are diagnosed with hepatic disorders, 2 with neurological degeneration and 1 with both hepatic and neurological disorders. METHODS: All ATP7B coding regions were analyzed by Sanger sequencing. Single nucleotide polymorphisms (SNPs) functional impacts were assessed by combining the results of four bioinformatics tools (Poly-phen-2, SIFT, PANTHER-PSEP and PhD-SNPs) in an index that reflects the combined probability (cPdel) of an amino acid change to be deleterious to the protein function. RESULTS: Two novel variants involved in WD development, c.1448_1455del (p.Arg483SerfsX19) and c.4144G>T (p.Glu1382Stop), and 11 previously reported mutations were detected. Both new variants result in shortened and dysfunctional ATP7B proteins. cPdel score suggests that SNPs may be deleterious to the ATP7B functionality. CONCLUSIONS: This study enriches the library of the ATP7B mutations that lead to WD and can be used as a basis for genetic counseling, for WD prevention and clinical and prenatal diagnosis. Those SNPs that are believed to be harmless to ATP7B protein may be involved in the pathogenesis of WD.

Apolipoprotein E deletion has no effect on copper-induced oxidative stress in the mice brain.

The current study was designed to investigate effect of copper administration on oxidative damage to the brain in ApoE-/- mice and to explore the putative neuroprotective effects rendered by apolipoprotein E (ApoE). Male C57BL/6 ApoE-/- and wild-type mice were randomly assigned into four groups, ApoE-/- mice wild-type mice treated with either copper or saline. Copper sulphate pentahydrate or saline (200 µl) were administered intragastrically daily for 12 weeks. Expression of malondialdehyde, superoxide dismutase (SOD), hemeoxygenase 1 (HO-1), and NAD(P)H: quinone oxidoreductase 1 (NQO1) were determined by a combination of biochemical assays. The concentration of copper in the brain of C57BL/6 mice and ApoE-/- mice treated by copper significantly increased compared with mice treated by saline (P=0.0099 and P=0.0443). Compared with the C57BL/6 mice treated by copper, the level of the ApoE-/- mice treated by copper was higher (P=0.018). TBARS and SOD activities or the expressions of NQO1 and HO-1 in the brain were not significantly different amongst the four experimental groups of mice. The relative value of NQO1/ß-actin expression in the brain of the ApoE-/- mice was similar in both saline and copper administration experimental groups. However, Western blot analysis showed that NQO1 expression was significantly higher in the ApoE-/- mice brain treated with saline compared with saline treated wild-type mice (P=0.0449). ApoE does not function in protecting the brain from oxidative damage resulting from copper build-up in Wilson's disease, but may play a role in regulating copper accumulation in the brain.

Expanded newborn screening by mass spectrometry: New tests, future perspectives.

Tandem mass spectrometry (MS/MS) has become a leading technology used in clinical chemistry and has shown to be particularly sensitive and specific when used in newborn screening (NBS) tests. The success of tandem mass spectrometry is due to important advances in hardware, software and clinical applications during the last 25 years. MS/MS permits a very rapid measurement of many metabolites in different biological specimens by using filter paper spots or directly on biological fluids. Its use in NBS give us the chance to identify possible treatable metabolic disorders even when asymptomatic and the benefits gained by this type of screening is now recognized worldwide. Today the use of MS/MS for second-tier tests and confirmatory testing is promising especially in the early detection of new disorders such as some lysosomal storage disorders, ADA and PNP SCIDs, X-adrenoleucodistrophy (X-ALD), Wilson disease, guanidinoacetate methyltransferase deficiency (GAMT), and Duchenne muscular dystrophy. The new challenge for the future will be reducing the false positive rate by using second-tier tests, avoiding false negative results by using new specific biomarkers and introducing new treatable disorders in NBS programs.

Impact of the discovery of human zinc deficiency on health.

The essentiality of zinc in humans was established in 1963. During the past 50y, tremendous advances in both clinical and basic sciences of zinc metabolism in humans have been observed. Growth retardation; cell-mediated immune dysfunction, and cognitive impairment are major clinical effects in human. At present we know of >300 enzymes and >1000 transcription factors that require zinc for their activities. Zinc is a second messenger of immune cells, and intracellular free zinc in these cells participate in signaling events. Zinc has been very successfully used as a therapeutic modality for the management of acute diarrhea in children, Wilson's disease, the common cold and for the prevention of blindness in patients with age-related dry type of macular degeneration. Zinc not only modulates cell-mediated immunity but is also an antioxidant and anti-inflammatory agent. Zinc supplementation in the elderly results in decreased incidence of infections, decreased oxidative stress and decreased generation of inflammatory cytokines.

Compliant treatment with anti-copper agents prevents clinically overt Wilson's disease in pre-symptomatic patients.

BACKGROUND AND PURPOSE: Wilson's disease (WD) is an inherited copper metabolism disorder that leads to dysfunction of affected tissues, mostly in the liver and brain. Anti-copper treatment should prevent clinically overt WD in pre-symptomatic patients but this has not been supported by strong evidence. Our aim was to evaluate the long-term effectiveness of treatment in clinically pre-symptomatic patients, with particular emphasis on patient compliance with treatment. METHODS: Data were analyzed for 87 consecutive patients with no clinical symptoms of WD who were identified between 1957 and 2009 by family screening. All of them since diagnosis were treated with either zinc sulphate (Zn) (66.7%) or D-penicillamine (DPA) (33.3%). RESULTS: During a median follow-up of 12 years (range 3-52), 55 (63%) patients remained without clinical symptoms, 13 (15%) developed neuropsychiatric symptoms and 21 (24%) developed hepatic dysfunction, including five deaths from hepatic failure. Non-compliance for at least three consecutive months was observed in 39 patients, and in 29 cases this extended for more than 12 months. Multivariate analysis showed that the odds of developing symptomatic WD were independently increased by non-compliance (odds ratio 24.0, 95% confidence interval 6.0-99.0). According to Kaplan-Meier analysis patients who were compliant to treatment had a significantly higher likelihood of remaining symptom-free, and their overall survival was similar to the survival rate observed in the general population. CONCLUSION: The use of anti-copper agents in clinically pre-symptomatic patients diagnosed with WD allows clinically overt disease to be effectively prevented. However, compliance with therapy is extremely important.

Wilson's disease: an analysis of 28 Brazilian children.

OBJECTIVES: Clinical-laboratory and evolutionary analysis of twenty-eight patients with Wilson's disease. METHODS: Twenty-eight children (twelve females and sixteen males) with Wilson's disease were evaluated retrospectively between 1987 and 2009, with a follow-up of 72 months (1 - 240 months). The clinical, laboratory, and histologic features at diagnosis were recorded at the end of the study. RESULTS: The median age at diagnosis was 11 years (2 - 18 years). Twelve patients were asymptomatic, seven had hepatitis symptoms, five had raised aminotransferase levels, three had hepatomegaly associated with neurological disorders, one had fulminant hepatitis with hemolytic anemia, and six patients presented with a Kayser-Fleischer ring. A histological analysis revealed that six children had chronic hepatitis, seven had cirrhosis, two had steatosis, one had portal fibrosis, and one had massive necrosis. The treatment consisted of D-penicillamine associated with pyridoxine for 26 patients. Adverse effects were observed in the other two patients: one presented with uncontrollable vomiting and the other demonstrated elastosis perforans serpiginosa. At the end of the study, all 26 treated patients were asymptomatic. Twenty-four of the patients were treated with D-penicillamine and pyridoxine, and two were treated with trientine and zinc sulfate. A liver transplant was performed in one patient with fulminant hepatitis, but the final patient died 48 hours after admission to the intensive care unit. CONCLUSIONS: Family screenings associated with early treatment are important in preventing Wilson's disease symptoms and potentially fatal disease progression. The study suggests that Wilson's disease must be ruled out in children older than two years presenting with abnormal levels of hepatic enzymes because of the heterogeneity of symptoms and the encouraging treatment results obtained so far.

Wilson's disease: an analysis of 28 Brazilian children

OBJECTIVES: Clinical-laboratory and evolutionary analysis of twenty-eight patients with Wilson's disease. METHODS: Twenty-eight children (twelve females and sixteen males) with Wilson's disease were evaluated retrospectively between 1987 and 2009, with a follow-up of 72 months (1 - 240 months). The clinical, laboratory, and histologic features at diagnosis were recorded at the end of the study. RESULTS: The median age at diagnosis was 11 years (2 - 18 years). Twelve patients were asymptomatic, seven had hepatitis symptoms, five had raised aminotransferase levels, three had hepatomegaly associated with neurological disorders, one had fulminant hepatitis with hemolytic anemia, and six patients presented with a Kayser-Fleischer ring. A histological analysis revealed that six children had chronic hepatitis, seven had cirrhosis, two had steatosis, one had portal fibrosis, and one had massive necrosis. The treatment consisted of D-penicillamine associated with pyridoxine for 26 patients. Adverse effects were observed in the other two patients: one presented with uncontrollable vomiting and the other demonstrated elastosis perforans serpiginosa. At the end of the study, all 26 treated patients were asymptomatic. Twenty-four of the patients were treated with D-penicillamine and pyridoxine, and two were treated with trientine and zinc sulfate. A liver transplant was performed in one patient with fulminant hepatitis, but the final patient died 48 hours after admission to the intensive care unit. CONCLUSIONS: Family screenings associated with early treatment are important in preventing Wilson's disease symptoms and potentially fatal disease progression. The study suggests that Wilson's disease must be ruled out in children older than two years presenting with abnormal levels of hepatic enzymes because of the heterogeneity of symptoms and the encouraging treatment results obtained so far.

The risks of free copper in the body and the development of useful anticopper drugs.

PURPOSE OF REVIEW: To review the toxicity and risks of free copper in Wilson's disease, Alzheimer's disease, other disease of neurodegeneration, and cognitive loss in the general population. We will also review the anticopper drugs and how lowering free copper levels with an anticopper drug inhibits fibrosis, inflammation, and autoimmunity. RECENT FINDINGS: Some exciting recent work indicates that free copper levels are increased in Alzheimer's disease, and copper may be involved in disease pathogenesis, opening the way to possible therapy of Alzheimer's disease with anticopper drugs. Copper may also be involved in other diseases of neurodegeneration. A very exciting recent study indicts high intake of copper, mostly from copper supplements, in conjunction with a high-fat diet in more rapid cognitive decline in the general population. Other data indicate that even low levels of copper in drinking water, perhaps similar to copper supplements, bypasses the liver, enters the circulation, increases the blood-brain penetration of copper, and may cause damage. SUMMARY: Some of the implications are that Alzheimer's disease and other diseases of neurodegeneration and fibrotic, inflammatory, and autoimmune diseases may be treatable by lowering the availability of free copper. People in the general population may wish to take steps to lower their free copper levels and, in particular, to abstain from taking copper supplements and ingesting significant amounts of copper in drinking water.

High incidence and allelic homogeneity of Wilson disease in 2 isolated populations: a prerequisite for efficient disease prevention programs.

OBJECTIVES: Herein we report the results of mutation-based screening for Wilson disease (WD) in 2 isolated populations of Sardinia and the Greek island of Kalymnos. PATIENTS AND METHODS: Mutation analysis was performed in 110 and 9 WD families originating respectively from Sardinia and Kalymons using single-strand conformation polymorphism and sequencing methods. In Sardinia, a limited screening was performed for -441/-427del in 5290 newborns, whereas in Kalymnos 397 newborns underwent mutation screening for H1069Q and R969Q using appropriate methods. RESULTS: In Sardinia, mutation analysis showed the presence of 6 mutations accounting for 85% of chromosomes, 1 of which (-441/-427del) is present in 61.7% of alleles. The screening for -441/-427del in 5290 newborns revealed the presence of 122 heterozygotes, which is equal to an allelic frequency of 1.15%. Assuming the same distribution of WD mutations in the general Sardinian population, we also inferred an allelic frequency of 0.77% for mutations other than -441/-427del, which accounts for an overall frequency of any WD mutation of 1.92%. Assuming Hardy-Weinberg equilibrium, these data could be translated into a WD incidence of 1 in 2707 live births. In Kalymnos, mutation analysis in 9 WD families revealed the presence of only 2 mutations. The screening of 397 newborns revealed the presence of 18 heterozygotes for H1069Q, 9 for R969Q, and 1 compound heterozygote for these mutations, which is equal to an allele frequency of 3.7%. Assuming Hardy-Weinberg equilibrium, the expected carrier rate is 7%. CONCLUSIONS: These data indicate the need for health education for WD prevention in these isolated populations.

Failure of prophylactic zinc in Wilson disease.

Early institution of prophylactic therapy of asymptomatic Wilson disease patients can prevent the expression of the disease. Zinc is currently preferred therapy for presymptomatic patients. We report onset of symptomatic disease in a presymptomatic patient and deterioration of biochemical parameters in another, despite appropriate zinc therapy.

Molecular diagnosis and prophylactic therapy for presymptomatic Chinese patients with Wilson disease.

BACKGROUND: The potential for therapy for Wilson disease (WD) emphasizes the importance of presymptomatic diagnosis in families with WD (WD families). OBJECTIVES: To investigate the feasibility of presymptomatic DNA diagnosis and evaluate the efficacy of zinc sulfate therapy in WD families. METHODS: Seventy-eight clinically unaffected siblings were studied from 51 unrelated WD families that were ascertained by affected individuals. The diagnosis in presymptomatic patients was established by a combination of direct mutational analysis and haplotype analysis with 3 short tandem repeat markers. The presymptomatic patients were treated with 50 mg of elemental zinc sulfate twice a day from the time of molecular diagnosis and followed up for 3 to 5 years. RESULTS: Of the 78 siblings, 17 were diagnosed as presymptomatic patients. Kayser-Fleischer rings were absent in 7 and faint in 4 of the 17 presymptomatic patients. The serum ceruloplasmin values gradually increased and 24-hour urinary copper values gradually diminished during zinc therapy, which indicate effective control of copper metabolism. None of the siblings developed clinical symptoms of WD or adverse effects from zinc therapy. CONCLUSION: We conclude that presymptomatic DNA diagnosis and zinc therapy are effective treatment of patients with WD.

Mass screening for Wilson's disease by measuring urinary holoceruloplasmin.

We conducted a mass-screening method to detect presymptomatic Wilson's disease in children by measuring urinary holoceruloplasmin. Two cases of Wilson's disease were found by testing urine samples from 48,819 children. The diagnosis was confirmed by clinical laboratory tests and the detection of a mutated ATP 7B gene.

A delicate balance: homeostatic control of copper uptake and distribution.

The cellular uptake and intracellular distribution of the essential but highly toxic nutrient, copper, is a precisely orchestrated process. Copper homeostasis is coordinated by several proteins to ensure that it is delivered to specific subcellular compartments and copper-requiring proteins without releasing free copper ions that will cause damage to cellular components. Genetic studies in prokaryotic organisms and yeast have identified membrane-associated proteins that mediate the uptake or export of copper from cells. Within cells, small cytosolic proteins, called copper chaperones, have been identified that bind copper ions and deliver them to specific compartments and copper-requiring proteins. The identification of mammalian homologues of these proteins reveal a remarkable structural and functional conservation of copper metabolism between bacteria, yeast and humans. Furthermore, studies on the function and localization of the products of the Menkes and Wilson's disease genes, which are defective in patients afflicted with these diseases, have provided valuable insight into the mechanisms of copper balance and their role in maintaining appropriate copper distribution in mammals.

Screening for Wilson's disease in patients with liver diseases by serum ceruloplasmin.

BACKGROUND/AIMS: A low serum ceruloplasmin level is considered a diagnostic test for Wilson's disease. To examine whether it is useful to detect presymptomatic patients with Wilson's disease, serum ceruloplasmin was determined by radial immunodiffusion (normal: 20-60 mg/dl) in all patients (n = 2867) admitted for evaluation of a liver disease in 1993 and 1994. METHODS: Patients with levels lower than 20 mg/dl were further evaluated by determination of serum copper concentration, urine copper excretion and ophthalmological examination. If possible, a liver biopsy was performed and the hepatic copper content was determined by flame atomic absorption spectroscopy. RESULTS: Seventeen patients had serum ceruloplasmin levels < 20 mg/dl. One had asymptomatic Wilson's disease (no Kayser-Fleischer rings or neurological symptoms). In the other 16 patients Wilson's disease was excluded. Based on elevated hepatic copper concentration, there were considered as heterozygous carriers of the WD gene. The remaining patients had various liver diseases (acute viral hepatitis in three, chronic hepatitis in two, drug-induced liver disease in three, alcoholic induced liver disease in two) or malabsorption (n = 3). CONCLUSIONS: The positive predictive value of low serum ceruloplasmin was only 5.9%. Although helpful for identifying presymptomatic Wilson's disease, screening by determination of serum ceruloplasmin in unselected patients with clinical or laboratory evidence of liver disease is neither feasible nor cost effective.

Intrahepatic transplantation of normal hepatocytes prevents Wilson's disease in Long-Evans cinnamon rats.

BACKGROUND & AIMS: Long-Evans cinnamon (LEC) rats are an animal model of Wilson's disease. This study investigated whether intrahepatic transplantation of normal hepatocytes can prevent Wilson's disease in LEC rats. METHODS: Hepatocytes of newborn Long-Evans agouti (LEA) rats were transplanted into the livers of LEC rats before onset of hepatic disease. Expression of normal transcripts from the gene linked to Wilson's disease was investigated at 30 weeks of age by reverse-transcription polymerase chain reaction and in situ hybridization. RESULTS: Eight of 16 (50.0%) untreated LEC rats died of hepatic failure during 20-30 weeks of age. Of the 27 LEC rats with transplanted cells, 2 (7.4%) died of hepatic failure and 4 died of ileus complicated by the surgical treatment. In the recipient livers, the transplanted cells comprised 4%-20% of the hepatocyte populations, expressing normal messenger RNA transcribed from the Wilson's disease gene, and hepatic copper deposition was reduced to approximately 60% of that in untreated LEC rats. CONCLUSIONS: Transplantation of normal hepatocytes prevents Wilson's disease in LEC rats.

[Abnormal hepatic copper accumulation and its significance in LEC rats developing spontaneous hepatitis and hepatoma].

The LEC rat is a mutant inbred strain isolated from Long-Evans rats, which spontaneously develops hepatitis and hepatoma with high frequency. In this study, copper profiles of LEC rats, including copper concentration in the liver and concentrations of copper and ceruloplasmin in the serum, were investigated. It was found that copper accumulated in the liver of LEC rats immediately prior to the onset of hepatitis with a concentration of more than 50 times that of normal LEA rats, and serum concentrations of copper and ceruloplasmin decreased markedly, which resembled biochemically characteristic features of human Wilson's disease. Administration of d-penicillamine (100 mg/Kg/day p. o), a chelating agent, reduced the hepatic copper level and completely inhibited the development of hepatitis in LEC rats. Copper also accumulated in both cancerous and non-cancerous liver tissues of three 29-month old male LEC rats which had spontaneously developed hepatocellular carcinomas. These findings suggest that the hepatitis in LEC rats is caused by copper toxicity, and that the abnormal copper metabolism may be involved in hepatic carcinogenesis in the LEC rats. Therefore, it is considered that the LEC rat will provide a promising animal model for not only elucidating the pathogenesis of Wilson's disease and developing treatment strategies of the disease, but also for studying the role of copper in hepatic carcinogenesis.