A genetical analysis of thirty families with Wilson's disease (hepatolenticular degeneration)

Wilson’s Disease—Genetic Puzzles with Diagnostic Implications

(1) Introduction: Wilson’s disease (WND) is an autosomal recessive disorder of copper metabolism. The WND gene is ATP7B, located on chromosome 13. WND is characterized by high clinical variability, which causes diagnostic difficulties. (2) Methods: The PubMed, Science Direct, and Wiley Online Library medical databases were reviewed using the following phrases: “Wilson’s disease”, “ATP7B genotype”, “genotype-phenotype”, “epigenetics”, “genetic modifiers”, and their combinations. Publications presenting the results of experimental and clinical studies, as well as review papers, were selected, which concerned: (i) the diversity of genetic strategies and tests used in WND diagnosis; (ii) the difficulties of genetic diagnosis, including uncertainty as to the pathogenicity of variants; (iii) genetic counseling; (iv) phenotypic effects of ATP7B variants in patients with WND and in heterozygous carriers (HzcWND); (v) genetic and epigenetics factors modifying the clinical picture of the disease. (3) Results and conclusions: The genetic diagnosis of WND is carried out using a variety of strategies and tests. Due to the large number of known variants in the ATP7B gene (>900), the usefulness of genetic tests in routine diagnostics is still relatively small and even analyses performed using the most advanced technologies, including next-generation sequencing, require additional tests, including biochemical evidence of abnormal copper metabolism, to confirm the diagnosis of WND. Pseudodominant inheritance, the presence of three various pathogenic variants in the same patient, genotypes indicating the possibility of segmental uniparental disomy, have been reported. Genotype–phenotype relationships in WND are complex. The ATP7B genotype, to some extent, determines the clinical picture of the disease, but other genetic and epigenetic modifiers are also relevant.

Copper-Induced Epigenetic Changes Shape the Clinical Phenotype in Wilson's Disease

Wilson's disease is a congenital disorder of copper metabolism whose pathogenesis remains, at least in part, unknown. Subjects carrying the same genotype may show completely different phenotypes, differing for the age at illness onset or for the hepatic, neurologic or psychiatric clinical presentation. The inability to find a unequivocal correlation between the type of mutation in the ATPase copper transporting beta (ATP7B) gene and the phenotypic manifestation, has encouraged many authors to look for epigenetic factors interacting with the genetic changes. Here, the evidences regarding the ability of copper overload to change the global DNA methylation status are discussed.

Copper Dyshomeostasis in Neurodegenerative Diseases-Therapeutic Implications

Copper is one of the most abundant basic transition metals in the human body. It takes part in oxygen metabolism, collagen synthesis, and skin pigmentation, maintaining the integrity of blood vessels, as well as in iron homeostasis, antioxidant defense, and neurotransmitter synthesis. It may also be involved in cell signaling and may participate in modulation of membrane receptor-ligand interactions, control of kinase and related phosphatase functions, as well as many cellular pathways. Its role is also important in controlling gene expression in the nucleus. In the nervous system in particular, copper is involved in myelination, and by modulating synaptic activity as well as excitotoxic cell death and signaling cascades induced by neurotrophic factors, copper is important for various neuronal functions. Current data suggest that both excess copper levels and copper deficiency can be harmful, and careful homeostatic control is important. This knowledge opens up an important new area for potential therapeutic interventions based on copper supplementation or removal in neurodegenerative diseases including Wilson’s disease (WD), Menkes disease (MD), Alzheimer’s disease (AD), Parkinson’s disease (PD), and others. However, much remains to be discovered, in particular, how to regulate copper homeostasis to prevent neurodegeneration, when to chelate copper, and when to supplement it.

Anemia following zinc treatment for Wilson's disease: a case report and literature review

Background

Zinc therapy is considered an effective and safe treatment for Wilson’s disease. Hypocupremia-related anemia is rarely reported after long-term zinc administration or combination therapy with copper-chelating agent.

Case presentation

We herein report a 12-year-old girl with pre-symptomatic Wilson’s disease diagnosed 5 years ago who presented with severe anemia after high-dose oral zinc for 4 years and 4 months. Her hemoglobin was gradually restored to the normal range after the adjustment of zinc dose and diet therapy for 4 months. A review of the literature revealed eight patients with hypocupremia-associated anemia following zinc therapy for Wilson’s disease, including 7 adults and 1 child. The only child patient was a 16-year-old boy, in whom the zinc therapy was succession to penicillamine administration.

Conclusions

This is the first report worldwide that a child developed severe anemia following high-dose single zinc administration for Wilson’s disease. It highlights the importance of regular follow-up during zinc treatment and the involvement of specialists in the long-term management of Wilson’s disease. We hope that this will alert pediatricians the issue of zinc over-treatment.

Psychiatric comorbidity in Wilson's disease

Wilson's disease (WD) is a relatively rare autosomal recessive inherited disorder causing copper accumulation in different organs, mainly the liver and brain. Psychiatric disturbances represent a diagnostic and therapeutic issue in WD. A search for relevant articles was carried out on PubMed/Medline, Scopus, and Google Scholar, for papers focused on psychiatric disorders in WD published between 1985-2016. Ninety-two articles were included in this review, showing the findings from 35 observational and case-control studies and 57 case reports. This study discussed the findings on the prevalence of psychiatric symptoms in WD, their impact on the life of those diagnosed, and the efficacy of available treatments on the psychiatric outcomes of WD. Psychiatric disorders are confirmed frequent in WD, with a high prevalence of mood disorders, and contribute to worse Quality-of-Life and psychosocial outcomes. Because specific therapies for WD lead to a good life expectancy, adherence to medicaments and clinical monitoring should be warranted by a multidisciplinary approach, including a hepathologic, neurologic, and psychiatric careful evaluation and education of those affected and their relatives.

History of Wilson disease: a personal account

This chapter focuses on the historic aspects of the development of much of our current knowledge of the diagnosis and treatment of Wilson disease. Included are descriptions of the clinical signs of neurologic and hepatic disease, the natural history of disease progression, studies of disease pathogenesis and a unique perspective on the development of diagnostic testing and pharmacological therapy.

Electro Convulsive Therapy in Psychiatric Manifestations in Wilson's Disease

Wilson's disease occurs due to an inborn error of metabolism. Psychiatric symptoms are often the first manifestation of the disease and can obscure the diagnosis. There are five neuropsychiatric symptoms clusters established for Wilson's disease patients: Behavior and/or personality disorders, mood disorders, cognitive deficits, psychotic manifestations, and others. The frequency with which psychiatric manifestations appears in Wilson's disease remains vague. However, whenever they occur, they need to be correctly identified and treated. Though encouraging results have been obtained in controlling psychiatric manifestations of Wilson's with psychotropic medications, some sub-group of patients fail to respond to any therapy. We aim at finding options for controlling psychosis in these patients with electro convulsive therapy (ECT). A patient exhibiting rare neuropsychiatric manifestations of Wilson's and who is not responding to psychotropic medication was considered for ECT. Considerable control over psychiatric manifestations with ECT was observed and later treated with maintenance ECTs for relapse control.

Quality of Life and Psychiatric Symptoms in Wilson's Disease: the Relevance of Bipolar Disorders

INTRODUCTION

Wilson's disease is an inherited disorder caused by a gene located on chromosome 13, which involved copper transportation across cell membranes. The disease can cause a reduced incorporation of copper into ceruloplasmin resulting in accumulation of this metal in the liver, central nervous system, kidneys and other organs. The objective is to define the frequencies of psychiatric disorders in WD, the amount of impairment of Quality of Life [QoL] in patients with WD and the relevance of the psychiatric disorders in the QoL of people suffering by WD.

METHODS

This is a systematic review. The search of the significant articles was carried out in PubMed using specific key words.

RESULTS

Such other neurological diseases, WD is characterized by chronic course and need of treatments, impairment of functional outcomes and high frequency of psychiatric symptoms, although a specific association between Bipolar Disorders and WD was recently found. Despite this, since today few studies are carried on WD patients' quality of life related to psychiatric symptoms. Some new reports showed a link between presence of Bipolar Disorders diagnosis, cerebral damage and low Qol.

CONCLUSION

Prospective studies on large cohorts are required to establish the effective impact of psychiatric disorders comorbidity, particularly Bipolar Disorders, on quality of life in WD and to clarify the causal link between brain damage, psychiatric disorders and worsening of QoL.

Presentation, diagnosis and outcome of predominantly hepatic Wilson's disease in adult Saudi patients: a single centre experience

BACKGROUND/AIM

To evaluate the clinical manifestations, diagnostic features, disease course and response to treatment among Saudi adults with predominantly hepatic Wilson's disease. A retrospective cohort study of 40 adult patients diagnosed with predominantly hepatic Wilson's disease between 1994 and 2008 at King Abdulaziz Medical City, Riyadh was carried out.

PATIENTS AND METHODS

The diagnosis was based on varying combinations of clinical and laboratory evidence of liver disease, presence of Kayser Fleisher rings, low serum ceruloplasmin levels, elevated 24 hour urinary copper excretion and histopathological findings on liver biopsy.

RESULTS

The most frequent clinical presentation was decompensated chronic liver disease in 19 (47.5%), followed by chronic hepatitis in 15 (37.5%) and fulminant hepatic failure (FHF) in 5 (12.5%) patients. Eight (20%) patients with end-stage liver disease had liver transplantation, while 24 (60%) patients followed up on medical treatment for a variable period of 1-12 years showed clinical and laboratory improvement. One patient was lost early in follow up. Eight (20%) patients died during the study period, 5 with FHF, and 2 with advanced hepatic and neurological disease and one seven years after liver transplantation. Mortality rate was 100% in FHF without liver transplantation.

CONCLUSION

A predominantly hepatic Wilson's disease has varied clinical presentations with decompensated chronic liver disease being the most common among adult patients. Majority of the patients show stabilization of the disease on medical treatment. FHF in Wilson's disease has a grave prognosis without liver transplantation, the later remains a definitive treatment option for decompensated cirrhotics and patients with FHF.

Wilson's disease

In the almost 100 years since Wilson's description of the illness that now bears his name, tremendous advances have been made in our understanding of this disorder. The genetic basis for Wilson's disease - mutation within the ATP7B gene - has been identified. The pathophysiologic basis for the damage resulting from the inability to excrete copper via the biliary system with its consequent gradual accumulation, first in the liver and ultimately in the brain and other organs and tissues, is now known. This has led to the development of effective diagnostic and treatment modalities that, although they may not eliminate the disorder, do provide the means for efficient diagnosis and effective amelioration if carried out in a dedicated and persistent fashion. Nevertheless, Wilson's disease remains both a diagnostic and treatment challenge for physician and patient. Its protean clinical manifestations make diagnosis difficult. Appropriate diagnostic evaluations to confirm the diagnosis and institute treatment can be confusing. In this chapter, the clinical manifestations, diagnostic evaluation, and treatment approaches for Wilson's disease are discussed.

Hepatocellular carcinoma in a case of Wilson's disease treated with radiofrequency ablation therapy

A 37-year-old Japanese man was diagnosed with liver cirrhosis due to Wilson's disease in 2001 and treated with D-penicillamine. Thereafter, he was admitted to our hospital for further examination of a space occupying lesion in the liver. The patient was diagnosed with hepatocellular carcinoma (HCC) (7th segment, 2.5 cm in diameter) in May 2010 and treated with radiofrequency ablation therapy. Biopsy findings from a non-cancerous area revealed a fatty liver, though cirrhotic nodules were not found. Long-term treatment for Wilson's disease may improve hepatic fibrosis, and careful screening for HCC by abdominal imaging is needed in such cases.

High prevalence of fulminant hepatic failure among patients with mutant alleles for truncation of ATP7B in Wilson's disease

OBJECTIVE

Although many mutations of the Wilson's disease (WD) gene (ATP7B) have been reported, few data exist regarding the occurrence of fulminant hepatic failure (FHF). We sought to determine if genotypic assignment according to type of protein-product could be related to the prevalence of FHF among patients with WD.

MATERIAL AND METHODS

We performed gene analysis in Japanese patients with WD as well as genotype-phenotype analysis in 51 patients. We divided genotypes into two groups according to type of ATP7B product: truncated group [T] consisted of two truncated alleles including nonsense, insertion, deletion, or splice site mutation, and missense group [M] consisted of one or two missense alleles. We also divided phenotypes into two groups: [FHF] group and [non-FHF] group.

RESULTS

We were able to determine genotype in 42 patients. Genotypically, 11 patients were assigned to [T] group and 31 to [M] group. Phenotypically, 4 patients were [FHF] and 38 were [non-FHF]. All patients in [FHF] group belonged to [T] group. The prevalence of [FHF] in [T] group was 36.4% and was significantly higher than in [M] group (p < 0.003).

CONCLUSIONS

These results demonstrated that genotypes for truncation of ATP7B are associated with high prevalence of FHF.

Neurologic Wilson's disease

Despite a long history, Wilson's disease, an autosomal recessive disease caused by mutations in the ATP7B gene, remains a commonly misdiagnosed import disease. Mutations in ATP7B result in abnormal copper metabolism and subsequent toxic accumulation of copper. Clinical manifestations of neurologic Wilson's disease include variable combinations of dysarthria, dystonia, tremor, and choreoathetosis. Among neurodegenerative diseases, it is unusual in that misdiagnosis and delay in treatment are clinically relevant because treatments can prevent and cure Wilson's disease, if they are given appropriately. If left untreated, Wilson's disease progresses to hepatic failure or severe neurologic disability and death, while those adequately treated have normal life spans. This review focuses on the neurologic features of Wilson's disease, its diagnosis, and treatment options.

Systematic review: clinical efficacy of chelator agents and zinc in the initial treatment of Wilson disease

BACKGROUND

No consensus is available on the optimal initial treatment in Wilson disease.

AIM

To assess systematically the available literature of treatment in newly presenting patients with a presymptomatic, hepatic or neurological presentation of Wilson disease.

METHODS

A systematic literature search of the MEDLINE, EMBASE and COCHRANE databases was performed. Original studies on clinical efficacy of D-penicillamine, trientine, tetrathiomolybdate or zinc monotherapy as initial treatment in Wilson disease were included. A descriptive analysis of the relevant published data was performed.

RESULTS

One randomized trial and 12 observational studies met the inclusion criteria. These studies were quite heterogeneous and generally of low validity. Nevertheless, according to currently available data, patients with hepatic presentation of Wilson disease are probably most effectively treated by D-penicillamine. Zinc seems to be preferred above d-penicillamine for treatment of presymptomatic and neurological patients, as in these subgroups, the tolerance profile is in favour of zinc, while no obvious differences in clinical efficacy could be observed.

CONCLUSIONS

There is lack of high-quality evidence to estimate the relative treatment effects of the available drugs in Wilson disease. Therefore, multicentre prospective randomized controlled comparative trials are necessary.

Chapter 33: the history of movement disorders

Role of basal ganglia: Vesalius and Piccolomini distinguished subcortical nuclei from cortex and white matter in the 16th century. Willis' mistaken concept in the late 17th century that the corpus striatum was the seat of motor power persisted for 200 years and formed the basis of mid-19th-century localizations of movement disorders to the striatum (chorea by Broadbent and Jackson, and athetosis by Hammond). By the late 19th century, many movement disorders were described but for most no pathologic correlate was known. Tremor: Descriptions of tremors progressed from Galen's definition in the 2nd century; to Galileo's physiologic tremor in 1610; separation of involuntary movements during action and at rest in the 17th and 18th centuries by de la Boë Sylvius and van Sweiten; description of Parkinson's disease by Parkinson, discrimination of the rest tremor of Parkinson's disease from the intention tremor of multiple sclerosis by Charcot, and recognition of familial action tremors by Dana and others in the late 19th century; and recognition of autosomal dominant essential tremor in the mid-20th century. Parkinsonism: Pathologic changes in Parkinson's disease were recognized in the substantia nigra by Blocq and Marinescu in the late 19th century, and around 1920 Trértiakoff established Lewy bodies in the substantia nigra as a pathologic hallmark while the Vogts instead emphasized pathologic changes in the striatum; it was only in the mid-1960s that a nigrostriatal dopaminergic pathway was demonstrated and found to be critical to pathogenesis. Early treatment approaches with anticholinergic medications or crude neurosurgical ablation procedures were eclipsed in the 1960s by the advent of L-DOPA therapy due to the work of Carlsson and colleagues, Birkmayer and Hornykiewicz, Barbeau, and Cotzias. Later progress in understanding and treating Parkinson's disease included recognition of neuroleptic-induced parkinsonism beginning in the 1950s, development of dopamine agonists and elaboration of different dopamine receptors beginning in the 1960s, recognition of MPTP-induced parkinsonism in 1982 and subsequent development of experimental models of MPTP-induced parkinsonism. Since the 1980s, stereotactic neurosurgical ablation procedures such as stereotactic pallidotomy were revisited and improved, and stimulation or ablation procedures that modulate subthalamic nucleus activity were developed. Since 1990, rare genetic forms of Parkinson's disease were discovered, which accelerated progress in understanding pathogenesis, and established roles for alpha synuclein and the ubiquitin-proteasome proteolytic system. Separation of atypical forms of parkinsonism (e.g. Wilson's disease, multisystem atrophy, progressive supranuclear palsy, and corticobasal degeneration) from Parkinson's disease in the 20th century also led to important discoveries of basal ganglia function, and in the case of Wilson's disease to recognition of genetic mutations and effective treatments. Choreoathetosis: Since the middle ages, the term chorea has been used to describe both organic and psychological disorders of motor control. Paracelcus introduced the concept of chorea as an organic medical condition in the 16th century. Sydenham's description of childhood chorea (1686) was followed by recognition in the 19th and 20th centuries that Sydenham's chorea was a manifestation of rheumatic fever; by the 1930s, rheumatic fever was recognized as a sequel of group A streptococcal pharyngitis, which could be effectively prevented with sulfonamides. Athetosis was described by Hammond (1871) and later linked by him to a malignant growth in the contralateral corpus striatum; nevertheless, athetosis has been controversial and often dismissed as a form of post-hemiplegic chorea or part of a continuum between chorea and dystonia. Huntington's classic description of adult-onset hereditary chorea (1872) was followed a century later by demonstration that Huntington's disease is caused by an unstable CAG trinucleotide repeat expansion in the Huntington disease gene on chromosome 4; this triggered a surge in research, development of various animal models, and numerous important discoveries of cell function and disease pathogenesis. Hemiballismus and the subthalamic nucleus: The relationship between a lesion of the subthalamic nucleus of Luys and contralateral hemiballismus was first convincingly demonstrated by Martin in 1927; this led 20 years later to development of an animal model by Whittier and Mettler, who produced experimental hemichorea-hemiballismus in monkeys by lesioning the contralateral subthalamic nucleus. Since the late 1980s, the neurochemistry and neurophysiology of the subthalamic nucleus have been substantially revised with the demonstration that the subthalamic nucleus is not fundamentally inhibitory but instead provides excitatory glutaminergic inputs to the globus pallidus, and appreciation that the subthalamic nucleus serves an important role in both hyperkinetic and hypokinetic movement disorders. Dystonia: Dystonias were often interpreted in psychological or psychiatric terms since the original descriptions of generalized dystonia by Barraquer Roviralta (1897), and familial forms of generalized primary tortion dystonia by Schwalbe (1908) and Oppenheim (1911). Although Oppenheim had first insisted that dystonia was an organic disease, it was only in the late-20th century that an organic framework was firmly established with the identification of genetic mutations in some families with dystonia and with the demonstration that the basal ganglia were often damaged contralateral to acquired hemidystonia. Focal and segmental forms of dystonia, including writer's cramp, other occupational dystonias, and torticollis, were also recognized in the 19th century. Writer's cramp was clearly described in the 1830s by Bell and Kopp, and increasingly recognized in the late 19th century due in part to Solly's influential lectures on "scriviner's palsy" in the 1860s, and to increasing prevalence because of the increase in writing using primitive writing instruments. Myoclonus: In 1903, Lundborg proposed a classification of myoclonus that remains in use, with primary (essential), epileptic, and secondary or symptomatic categories: essential myoclonus was described by Friedrich in 1881; forms of myoclonic epilepsy were described beginning in the late 19th century by West (1861), Unverricht (1891), and Lundberg (1903); and secondary multifocal myoclonus was recognized in a wide variety of disorders beginning in the 1920s. Asterixis was described in patients with hepatic encephalopathy by Adams and Foley in 1949 and found to result from electrically silent pauses in muscle activity, which led to the concept of negative myoclonus in the 1980s. Posthypoxic action myoclonus (Lance-Adams syndrome) was described by Lance and Adams in 1963 and found to incorporate both positive and negative components. Startle syndromes: Early descriptions of pathologic startle syndromes included Beard's description of the jumping Frenchmen of Maine (1878) and Hammond's description of miryachit (1884), both of which may have had psychological origins. In contrast, hyperekplexia or "startle disease" was described in the late 1950s and early 1960s, and genetic forms were later found to result from various mutations affecting glycinergic synapses. Tics: Tic disorders were described by Itard (1825) and Trousseau (1873), but only gained wider recognition in the late 19th century after Charcot presented cases before his classroom audiences and after Gilles de la Tourette's classic description in 1885. Gilles de la Tourette and Charcot initially considered tic disorders and startle syndromes to be similar if not identical, but these disorders were later recognized as distinct. Psychodynamic and psychological theories or etiology gave way in the 1960s to biological theories supporting an important role for dopamine in pathogenesis, particularly with the discovery that neuroleptic medications could be useful in treatment.

CONCLUSION

In the last two centuries, neuroscientists and clinicians contributed greatly to our understanding of basal ganglia anatomy and physiology, as well as to movement disorder semiology, pathophysiology, treatment, and prevention. The development of animal models, and the increasing use of genetic and molecular biological techniques will lead to further advances in the coming years.

Liver imaging findings of Wilson's disease

Wilson's disease is a rare, autosomal-recessive inherited disorder of copper metabolism resulting in accumulation of copper in liver. The form of liver disease varies, depending on the severity of the disease at the time of diagnosis and pathological findings include fatty changes, acute hepatitis, chronic active hepatitis, cirrhosis and occasionally fulminant hepatic necrosis. Liver imaging findings reflect a wide range of physiopathological processes of the disease and also demonstrate the associated findings of cirrhosis in cases with advanced disease.

Treatment of Wilson’s disease with zinc from the time of diagnosis in pediatric patients: A single-hospital, 10-year follow-up study

Wilson's disease (WD) is an inherited disorder of copper metabolism characterized by a failure of the liver to excrete copper, leading to its accumulation in the liver, brain, cornea, and kidney, with resulting chronic degenerative changes. It is generally accepted that "presymptomatic" patients--in whom WD is diagnosed in childhood and who are defined as those who, although still asymptomatic, do have liver disease, as indicated by increased serum concentrations of transaminases--should be treated prophylactically. Here we report our results in 22 children treated with continuous oral zinc therapy for 10 years. Zinc sulfate was administered at a dosage of 25 mg elemental zinc twice a day until the age of 6 years, 25 mg three times a day between the ages of 7 and 16 years or until the child attained a body weight of 125 lb, and 50 mg three times a day thereafter. Five years after the start of zinc treatment, we noted highly significant decreases in alanine aminotransferase (ALT), aspartate aminotransferase (AST), and urinary copper excretion, but white blood cell counts did not vary significantly. Six of 22 patients continued to demonstrate greater-than-normal ALT concentrations and only 1 patient demonstrated an ALT concentration more than 1.5 times the upper normal limit. Further decreases in ALT, AST, and urinary copper excretion were observed at the end of the 10-year follow-up, but these decreases were not statistically significant. Only 1 patient continued to demonstrate abnormal ALT levels. Again, white blood cells showed no significant variations. All histologic scores (steatosis, inflammation, and fibrosis) were significantly decreased after treatment. Hepatic copper content was also significantly decreased, although it remained higher than normal in all patients. The removal of toxic copper was confirmed by disappearance of Kayser-Fleischer rings in 3 patients. Zinc did not have adverse effects on growth. The efficacy of zinc in WD in presymptomatic pediatric patients has been established in previous studies, and our study adds considerably to the earlier findings because it includes a large number of very young children, as many as 11 younger than 6 years and 20 younger than 10. The excellent clinical results in all patients, coupled with the improvement in hepatic histologic findings in the vast majority, indicate convincingly that zinc treatment can control the disease effectively and safely, preventing its progression over the course of 10 years. Histologic findings reportedly improved in 3 patients treated in an earlier study, but our data are numerically much more relevant. Notably, histologic study of the liver revealed that copper concentration was reduced by treatment, suggesting that oral zinc was able not only to prevent further accumulation of copper but also to promote, at least in part, the depletion of its stores. The lack of adverse effects of zinc on growth suggests that our patients received enough anticopper therapy to prevent damage resulting from copper toxicity but an adequate amount of copper for proper growth and development. In conclusion, our findings indicate that zinc is the treatment of choice in presymptomatic pediatric patients with WD.

The copper-transporting ATPases, menkes and wilson disease proteins, have distinct roles in adult and developing cerebellum

Copper is essential for brain metabolism, serving as a cofactor to superoxide dismutase, dopamine-beta-hydroxylase, amyloid precursor protein, ceruloplasmin, and other proteins required for normal brain function. The copper-transporting ATPases ATP7A and ATP7B play a central role in distribution of copper in the central nervous system; genetic mutations in ATP7A and ATP7B lead to severe neurodegenerative disorders, Menkes disease and Wilson disease, respectively. Although both ATP7A and ATP7B are required, their specific roles and regulation in the brain remain poorly understood. Using high-resolution imaging and functional assays, we demonstrate that ATP7A and ATP7B show cell-specific distribution in adult cerebellum, have distinct enzymatic characteristics, and are regulated differently during development. ATP7B is continuously expressed in Purkinje neurons (PN) where it delivers copper to the ferroxidase ceruloplasmin. ATP7A is a faster copper transporter than Wilson disease protein as evidenced by faster rates of catalytic reactions. The expression of ATP7A switches during development from PN to Bergmann glia, the cells supporting PN function in adult brain. Inactivation of ATP7B (Wilson disease protein) by gene knock-out induces a striking shift in the expression of the ATP7B target protein, ceruloplasmin, from PN to Bergmann glia, where ATP7A (Menkes disease protein) is present. The induced cell-specific change in expression restores copper delivery to ceruloplasmin via ATP7A. Overall, the results provide evidence for distinct functions of ATP7A and ATP7B in the cerebellum and illustrate a tight link between copper homeostasis in PN and Bergmann glia.

Wilson disease

Wilson disease (WD) is an autosomal recessive disorder of copper metabolism. Since daily copper intake exceeds the body's requirements, effective means of excreting excess copper are essential. These are accomplished by ATP7B, a new member of the cation-transporting p-type ATPase family, which is mainly expressed in the liver and mediates both copper secretion into plasma (coupled with ceruloplasmin synthesis) and its excretion into bile. Thus far, more than 200 mutations of the WD gene have been detected, causing impairment of ATP7B function and, ultimately, copper accumulation. Excess copper, however, induces free-radical reactions and lipid peroxidation. Resultant liver damage leads to steatosis, inflammation, cirrhosis, and, occasionally, fulminant liver failure. The diagnosis of WD is commonly made on the basis of typical clinical and laboratory findings, including low serum ceruloplasmin, increased urinary copper excretion, and increased hepatic copper content. Since liver morphology is non-specific, and copper histochemistry may lead to both false-negative and false-positive results, the pathologist usually only suspects the disease or assists in its confirmation. Although the value of molecular genetic testing is limited due to the high number of possible gene mutations, polymerase chain reaction may be useful for the evaluation of family members of homozygous index patients.

Mutational analysis of ATP7B and genotype-phenotype correlation in Japanese with Wilson's disease

The gene ATP7B responsible for Wilson's disease (WD) produces a protein which is predicted to be a copper-binding P-type ATPase, homologous to the Menkes disease gene (ATP7A). Various mutations of ATP7B have been identified. This study aimed to detect disease-causing mutations, to clarify their frequency and distribution, to determine whether genotype correlates with phenotype, and to determine the rate of abnormal findings in heterozygotes for the WD gene. We analyzed 41 unrelated Japanese WD families, including 47 patients. Twenty-one mutations, including nine novel ones, were identified. 2871delC (15.9%), 1708-5T-->G (11. 0%), and Arg778Leu (13.4%) were the most common mutations. 2871delC was detected mainly in eastern Japan and 1708-5T-->G in western Japan. The homozygotes for the 1708-5T-->G, 2871delC, or Arg778Leu mutations did not show a correlation with their phenotypes. Ceruloplasmin and copper levels were abnormally low in 28.6% and 35. 0% of heterozygotes, respectively. When patients and their families are screened for WD, a high rate of abnormal laboratory data in heterozygotes must be taken into account.

Wilson's disease

During the last 90 years, Wilson's hepatolenticular degeneration has evolved from a disease presenting insurmountable challenges to the clinician's diagnostic acumen to a metabolic disorder which is diagnosable woth certainty, treatable successfully, and even preventable. It may be long before the genetic defect becomes amenable to correction and a cure of the disease becomes possible.

Expression of the Wilson disease gene is deficient in the Long-Evans Cinnamon rat

Long-Evans Cinnamon rats develop a necrotizing hepatitis characterized by excessive hepatic copper accumulation, defective holoceruloplasmin biosynthesis and impaired biliary copper excretion. To elucidate the molecular basis of this defect, a cDNA clone encoding the rat Wilson disease gene was isolated and used to examine gene expression in selected tissues from normal and Long-Evans Cinnamon rats. Although this cDNA readily detects Wilson transcripts in liver and other tissues from normal rats, such transcripts are entirely absent from tissues derived from the Long-Evans Cinnamon rat strain. These data therefore identify the Long-Evans Cinnamon rat as the first bona fide animal model of Wilson disease and suggest that this rat strain may be a valuable resource in the study of this genetic disorder.

Geographic variations in Wilson's disease

Certain features of Wilson's disease (WD) in Asia have been found to be different from those in other continents. The higher prevalence rate in Japan is presumably due to a higher consanguinity rate. In Chinese there is a tight linkage between WD and two gene loci for esterase D and retinoblastoma in the long arm of chromosome 13. The high proportion of patients with hepatic presentation accounts for early onset of WD in the Japanese and Chinese series. Skeletal involvement, leg hyperpigmentation, dark complexion, amenorrhea, epileptic seizures, and cerebral white matter degeneration are relatively more common among WD patients in Asia. Excessive copper in the liver appears to have a protective effect against hepatocellular carcinoma and type B hepatitis. Electrophysiological studies suggest widespread functional disturbances of the CNS in WD. Side-effects from penicillamine are rather frequent and often lead to interruption of the therapy. Trien is found to be effective without adverse reactions. Oral zinc therapy may be a suitable alternative for long-term management of WD patients in developing Asian countries.

Wilson's disease in Israel: a genetic and epidemiological study

Clinical and family history data on persons affected with Wilson disease (WD) living in Israel between 1958 and 1984 were ascertained from the literature, hospital records and neurological and gastroenterological clinics. From this population of 51 families, representing a diversity of Middle Eastern. North African and European backgrounds, blood samples were collected from affected individuals in 21 families, their parents, sibs and other relatives for quantitative determinations of plasma copper and ceruloplasmin, liver tests and DNA analysis. Although the majority of patients have the hepatic form of the disease, hepatic and neurological cases were found among all ethnic groups. In fact, affected sibs in several inbred families who most likely inherited two copies of the same mutant allele had different symptoms. Gene frequencies were calculated for each of the populations taking into account inbreeding, probability of ascertainment, and estimated incidence. Although many of these communities have gene frequencies which are comparable to worldwide estimates, high prevalence of disease is maintained by consanguineous mating patterns. Probabilities of WND genotypes were calculated for 129 unaffected relatives who had an a priori risk of inheriting at least one WND allele using information from 10 DNA markers closely linked to the WND locus. There was no evidence that multiple loci are responsible for the observed clinical variability in this sample of families. Furthermore, studies of serum copper and ceruloplasmin levels in unaffected relatives suggest that phenotypic variability in WD may be due in part to an interaction of the WND locus with other genetic or non-genetic modifiers such as age.

Presenting symptoms and natural history of Wilson disease

The presenting symptoms of Wilson disease and its natural history as related to age are described based on 283 cases collected in Japan. The disease presented with a variety of signs and symptoms; the most frequent were in order of frequency jaundice, dysarthria, clumsiness, tremor, drooling, gait disturbance, malaise and arthralgia. The mean age at onset of the disease was 12.0 years. Hepatic and osteoarthral symptoms developed early and neurological symptoms late. Fifty-eight cases developed neurological symptoms only, 28 cases had hepatic symptoms only, and in 26 cases hepatic symptoms were followed by neurological symptoms. A higher mortality rate was observed in hepatic, hepato-haematological and hepato-renal cases mainly due to acute hepatic failure resulting in death only a few weeks after onset. Cases having only neurological symptoms showed a more favourable prognosis with a longer survival.

Evidence for linkage between Wilson disease and esterase D in three kindreds: detection of linkage for an autosomal recessive disorder by the family study method

Wilson disease (WD) is an inherited disorder of copper metabolism that affects the brain, liver, and other organs. Our group recently reported close linkage between the locus for WD and a polymorphic red cell enzyme, esterase D (EsD), in a large inbred Israeli-Arab lineage. We have subsequently studied two unrelated Druze kindreds in order to confirm this linkage and more precisely define the distance between the two loci. The maximum likelihood estimate of recombination was determined to be zero with lod scores of 1.48 and 1.06 in each Druze family, respectively. The combined maximum lod score based on pooled results from the Israeli-Arab and Druze kindreds is 5.49 at theta = 0.03. WD is one of a few autosomal recessive disorders that has been mapped by classical family study methods. In this paper, the merits for using large, inbred families in linkage studies of rare recessive disorders are discussed. Major considerations for pedigree selection are size and number of constituent nuclear families, number and distribution of affected individuals, and pedigree structure that may provide information for determination of phase between the disease and marker loci.

Inborn errors of trace element metabolism

Genetic disorders of trace element transport are now known in humans, mice, dogs and cattle. Those involving copper have been known longest and are best known clinically. Effects due to copper deficiency are seen in Menkes' disease, in X-linked cutis laxa and in the X-linked series of mottled mutants in the mouse. Copper accumulation is also harmful, causing damage initially to the liver and later to the kidneys and brain in Wilson's disease, in some Bedlington terriers and in toxic milk mice. Zinc deficiency is seen in acrodermatitis enteropathica and in premature babies born to women who seem to secrete milk that is zinc-deficient, as is seen in lethal milk mice. Study of animal mutants, especially mutant mice, is helpful in understanding the human diseases and identification of the basic defects in trace element transport in these diseases is improving knowledge relevant to trace element nutrition.

Low content of hepatic reduced glutathione in patients with Wilson's disease

In five of six patients with symptomatic Wilson's disease (WD) with increased hepatic copper content, increased renal copper excretion, and decreased serum concentrations of ceruloplasmin, significantly low levels of hepatic reduced glutathione (GSH) were found. Three of these patients showed increased levels of oxidized glutathione which in part could account for the missing GSH. These changes may result from increased lipid peroxidation due to the rise of intracellular copper concentration. Furthermore, WD patients showed a 50% decrease in the activity of hepatic GSH S-transferases. From these results we conclude that the disturbance in the hepatic glutathione system of patients with symptomatic WD may contribute to the perpetuation of liver damage. These patients, additionally, may be predisposed to an increased sensitivity to drugs interacting with glutathione.

Epidemiologic study of hepatolenticular degeneration (Wilson's disease) in Sardinia (1902-1983)

From 1902 to 1983, 68 cases of hepatolenticular degeneration (HLD) were discovered in Sardinia, with a mean frequency, in reference to number of live births, of 27.7 and a sex ratio of 1.83. The prevalence of the disease was seen to be higher over the last few decades. With regard to the geographic distribution of the disease, 3 high-frequency areas were evident, in Barbagia, in Campidano, and in the area surrounding the city of Sassari. In 38.23% of cases, the clinical picture was of hepatoneurologic type; hepatic forms have become more frequent over the last decades. The first symptoms were observed at mean age of 15 years 8 months. The number of asymptomatic cases was fairly consistent (22.05%). The median survival rate in subjects who received inadequate therapy was 6 years 4 months. Only 3 patients of the 45 treated with adequate therapy died. The gene frequency, calculated by the application of Dahlberg's formula, was extremely high.

Gaucher's disease in South Africa

The adult non-neuropathic form of Gaucher's disease has been identified in 32 patients in 25 Ashkenazi Jewish kindreds in South Africa. The minimum prevalence in this population is 1 in 5000, with a gene frequency of 0.014 and a carrier rate of 1 in 36. On correction for bias resulting from possible under-ascertainment, these minimum figures become 1 in 4000, 0.0166, and 1 in 30, respectively. Confirmation of autosomal recessive inheritance was obtained by segregation analysis by the 'a priori' and 'simple sib' methods. The Ashkenazin of South Africa have their origins in Lithuania and it is evident that the high gene frequency in South Africa is a reflection of the genetic constitution of the immigrant population. The localisation of the Gaucher gene to Lithuania represents a further step in the determination of the early geographic distribution of the genetic disorders of the Jewish race.

Prognosis of Wilson's disease in childhood

Wilson's disease in childhood has several characters distinct from those in adults. The progression of the disease tends to be rapid, hepatic manifestations are common, cerebral symptoms related to dystonia are predominant, and tremor is rare. Forty-nine children with Wilson's disease under the age of 15 were treated with D-penicillamine for 2 to 15 years. None of the presymptomatic patients subsequently developed any symptoms of the disease. The results of treatment in patients who had exhibited only hepatic symptoms were also excellent. However, neurological manifestations associated with a history of jaundice or ascites responded less well to chelation. These observations clearly indicate that early diagnosis and treatment are extremely important to ensure normal lives for children with Wilson's disease.