Early Onset of Wilson Disease: Diagnostic Challenges

Clinical characteristics and prognosis of early diagnosed Wilson's disease: A large cohort study

BACKGROUND AND AIMS

Few studies have focused on the outcomes of Wilson's disease (WD) diagnosed before age of 5 years. This study aimed to summarize the clinical features of early diagnosed WD and analyse treatment outcomes and the risk factors associated with treatment failure.

METHODS

A total of 139 children confirmed with WD before 5 years were enrolled in this study. Only patients with follow-up over 1 year were analysed with Kaplan-Meier survival analysis. The composite outcomes included death, progression to liver failure or acute hepatitis, development of renal or neurological symptoms and persistent elevation of alanine aminotransferase (ALT). The treatment failure was defined as occurrence of at least one of above outcomes.

RESULTS

Among 139 WD patients at diagnosis, two (1.4%) WD patients presented with symptomatic liver disease, whereas 137 (98.6%) were phenotypically asymptomatic, including 135 with elevated ALT and 2 with normal liver function. Median serum ceruloplasmin (Cp) was 3.1 mg/dL, and urinary copper excretion was 87.4 μg/24-h. There were 71 variants identified in the the copper-transporting ATPase beta gene, and 29 were loss of function (LOF). 51 patients with LOF variant were younger at diagnosis and had lower Cp than 88 patients without LOF. Among 93 patients with over 1 year of follow-up, 19 (20.4%) received zinc monotherapy, and 74 (79.6%) received a zinc/D-penicillamine combination therapy. 14 (15.1%) patients underwent treatment failure, and its occurrence was associated with poor compliance (p < .01).

CONCLUSIONS

Cp is a reliable biomarker for early diagnosis, and zinc monotherapy is an effective treatment for WD during early childhood. Good treatment compliance is critical to achieve a favourable outcome.

Could Urinary Copper/Zinc Ratio Be a Newer Tool to Replace 24-Hour Urinary Copper Excretion for Diagnosing Wilson Disease in Children?

Purpose

Although the 24-hours urinary copper excretion is useful for the diagnosis of Wilson disease (WD), there are practical difficulties in the accurate and timed collection of urine samples. The purpose of this study was to verify if the spot morning urinary Copper/ Zinc (Cu/Zn) ratio could be used as a replacement parameter of 24-hours urinary copper excretion in the diagnosis of WD.

Methods

A cross-sectional study was conducted at the Department of Pediatric Gastroenterology and Nutrition, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh, from June 2019 to May 2021 on 67 children over three years of age who presented with liver disease. Twenty-seven children who fulfilled the inclusion criteria for WD were categorized into the test group, and the remaining forty children were considered to have non-Wilsonian liver disease and were categorized into the control group. Along with other laboratory investigations, spot morning urinary samples were estimated for the urinary Cu/Zn ratio in all patients and were compared to the 24-hour urinary copper excretion. The diagnostic value of the Cu/Zn ratio was then analyzed.

Results

Correlation of spot morning urinary Cu/Zn ratio with 24-hours urinary copper excretion was found to be significant (r=0.60). The area under ROC curve with 95% confidence interval of morning urinary Cu/Zn ratio measured using 24-hours urine sample was 0.84 (standard error, 0.05; p<0.001).

Conclusion

Spot morning urinary Cu/Zn ratio seems to be a promising parameter for the replacement of 24-hours urinary copper excretion in the diagnosis of WD.

Long-term outcome of patients with neurological form of Wilson's disease compliant to the de-coppering treatment

BACKGROUND

A substantial proportion of Wilson's disease (WD) patients exhibit residual neurological symptoms. Data on the prognostic value of initial clinical features and treatment choices in WD patients compliant to the therapy is relatively sparse.

AIM

The aim of the present study was to identify predictors of the long-term outcome of patients with WD with good treatment adherence.

METHODS

Forty patients with neurological form of WD were evaluated before the de-coppering treatment initiation (based on the medical records) and after mean 15.25 ± 11.24 years of the stable treatment. Severity of neurological symptoms were assessed with a tier two of Global Assessment Scale (GAS) for Wilson's Disease.

RESULTS

The most frequent symptoms prior to treatment initiation were dysarthria (90%), tremor (90%), clumsiness (67.5%), depression (67.5%), and gait disturbance (62.5%). Significant decrease in the frequency of dysarthria, clumsiness, tremor, gait disturbance, postural instability and an improvement in school/work performance were observed after the long-term treatment, while frequency of dysphagia, drooling, bradykinesia and rigidity, dystonic and choreatic features did not change. Overall symptom severity decreased over time. Presence of dystonia before treatment initiation was the only identified predictor of worse residual GAS score. Greater severity of residual dystonia was associated with female gender and longer disease duration.

CONCLUSION

Although patients with neurological form of WD compliant to de-coppering treatment had favorable disease outcome, a significant burden of residual neurological symptoms was observed after the long-term follow-up. Dystonia at disease onset was the only identified predictor of the worse long-term outcome.

Polarized trafficking and copper transport activity of ATP7B: a mutational approach to establish genotype-phenotype correlation in Wilson disease

Mutation in ATP7B gene causes Wilson disease (WD) that is characterized by severe hepatic and neurological symptoms. ATP7B localizes at the trans-Golgi Network (TGN) transporting copper to copper-dependent enzymes and traffics in apically targeted vesicles upon intracellular copper elevation. To decode the cellular underpinnings of WD manifestation we investigated copper-responsive polarized trafficking and copper transport activity of fifteen WD causing point mutations in ATP7B. Amino-terminal mutations Gly85Val, Leu168Pro and Gly591Asp displayed TGN and sub-apical localization whereas, Leu492Ser mislocalized at the basolateral region. The actuator domain mutation Gly875Arg shows retention in the endoplasmic reticulum (ER), Ala874Val and Leu795Phe show partial targeting to TGN and post-Golgi vesicles. The Nucleotide-Binding Domain mutations His1069Gln and Leu1083Phe also display impaired targeting. The C-terminal mutations Leu1373Pro/Arg is arrested at ER but Ser1423Asn shows TGN localization. Transmembrane mutant Arg778Leu resides in ER and TGN while Arg969Gln is exclusively ER localized. Cellular Cu level does not alter the targeting of any of the studied mutations. Mutants that traffic to TGN exhibits biosynthetic function. Finally, we correlated cellular phenotypes with the clinical manifestation of the two most prevalent mutations; the early onset and more aggressive WD caused by Arg778Leu and the milder form of WD caused by mutation His1069Gln. This article is protected by copyright. All rights reserved.

Assessment of the diagnostic value of serum ceruloplasmin for Wilson's disease in children

Background

Serum ceruloplasmin is one of the major diagnostic parameters for Wilson’s disease (WD). Age and gender difference of serum ceruloplasmin remain controversy. This study aims to assess diagnostic value of serum ceruloplasmin level for WD in children up to age of 15 years.

Methods

Serum ceruloplasmin levels were measured in 317 WD patients, 21 heterozygotes, 372 healthy control children and 154 non-WD patients with other liver diseases. Receiver operating characteristic (ROC) curve was used to determine the diagnostic accuracy of serum ceruloplasmin for WD in children.

Results

Among healthy controls, serum ceruloplasmin level was slightly low in the infants younger than 6 months, and then maintained from 26 to 33 mg/dl after age of 6 months. A total of 8.1% of healthy children had levels of serum ceruloplasmin < 20 mg/dL. Serum ceruloplasmin level was 5.7 ± 4.7 mg/dl in WD patients, and 25.6 ± 5.9 mg/dl in heterozygous carriers. Only 1.9% of WD patients had serum ceruloplasmin levels > 20 mg/dL. Serum ceruloplasmin levels had gender difference, being higher in healthy boys than healthy girls, and higher in asymptomatic WD boys than asymptomatic WD girls (p < 0.01, p < 0.05). Serum ceruloplasmin levels also presented genotypic difference. WD patients with R778L homozygotes exhibited lower levels of serum ceruloplasmin than the patients without R778L (p < 0.05). The ROC curve revealed that serum ceruloplasmin level, at a cutoff value of 16.8 mg/dL, had the highest AUC value (0.990) with a sensitivity of 95.9% and a specificity of 93.6%.

Conclusions

Serum ceruloplasmin is one of sensitive diagnostic biomarkers for WD in children. Gender and genotypic difference of serum ceruloplasmin level should be considered. The cutoff value of serum ceruloplasmin level < 16.8 mg/dL may provide the highest accuracy for diagnosis of WD in children.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02186-0.

Early Diagnosis of Wilson’s Disease in Children in Southern China by Using Common Parameters

Objective: The aim of the study was to develop the early diagnostic criteria for Wilson’s disease (WD) in young children in southern China by using alanine aminotransferase (ALT) elevation as the first manifestation.

Methods: A cross-sectional retrospective analysis of the clinical data and genetic test results of children with WD in southern China in the past 4 years and the follow-up of their short-term prognosis were performed in this study.

Results: A total of 30 children (5.08 ± 2.06 years old) with elevated ALT as the first manifestation of WD in southern China were enrolled in this study, including 14 females and 16 males. Specifically, in all of the 30 cases (100%), the serum ceruloplasmin (CP) level was decreased, whereas the 24-h urinary copper level was increased. The genetic mutation test of the ATP7B gene was used to confirm the diagnosis. In particular, the two mutation sites, including p.R778L and p.I1148T, had the highest mutation frequencies, approximately 23.0 and 10.7%, respectively. Through follow-up, most of the children had good recovery.

Conclusion: Early diagnosis and treatment of WD would substantially increase the survival rate and have a better prognosis. In addition, in 5-year-old children from southern China, early diagnosis could be performed quickly by referring to the following three parameters: elevated ALT, decreased ceruloplasmin level, and increased 24-h urinary copper level. It lays a foundation for further studies with a larger sample size.

Wilson's disease- management and long term outcomes

Wilson's disease (WD) is an autosomal recessive genetic disorder of copper metabolism leading to liver or brain injury due to accumulation of copper. Diagnosis is based on: clinical features, biochemical tests including plasma ceruloplasmin concentration, 24h urinary copper excretion, copper content in the liver, and molecular analysis. Pharmacological therapy comprises chelating agents (penicillamine, trientine) and zinc salts which seem to be very effective. Still, poor compliance is a major problem. Adolescents and patients with psychiatric disorders usually have problems with adherence to treatment. As transition is a vulnerable period transition ''training'' should start before the planned transfer, preferably already in early adolescence in cooperation between adult and pediatric clinics. Response to treatment is assessed based on physical examination, normal liver function tests and monitoring of copper metabolism markers. Liver transplantation has a well-defined role in Wilsonian acute hepatic failure according to the prognostic score. The long-term survival in WD patients seems to be very similar as for the general population if disease is early diagnosed and correctly treated. WD patients with a longer delay from diagnosis to therapy and who present with neurological and psychiatric symptoms have worse quality of life.

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.

Wilson disease

PURPOSE OF REVIEW

The aim of this article is to review recent developments in the areas of the disease features and treatment of Wilson disease, and survey disorders that share its pathophysiology or clinical symptoms.

RECENT FINDINGS

Knowledge of the clinical spectrum of Wilson disease has expanded with recognition of patients who present in atypical age groups - patients with very early onset (<5 years) and those in whom symptoms present in mid-to-late adulthood. A disease phenotype with dominant psychiatric features and increased risk of cardiac problems and various sleep disorders have been identified.In addition to a better understanding of the phenotype of Wilson disease itself, features of some related disorders ('Wilson disease-mimics') have been described leading to a better understanding of copper homeostasis in humans. These disorders include diseases of copper disposition, such as mental retardation, enteropathy, deafness, neuropathy, ichthyosis, keratoderma syndrome, Niemann-Pick type C, and certain congenital disorders of glycosylation, as well as analogous disorders of iron and manganese metabolism.Outcomes for existing treatments, including in certain patient subpopulations of interest, are better known. Novel treatment strategies being studied include testing of bis-choline tetrathiomolybdate in phase 2 clinical trial as well as various preclinical explorations of new copper chelators and ways to restore ATP7B function or repair the causative gene.

SUMMARY

Recent studies have expanded the phenotype of Wilson disease, identified rare inherited metal-related disorders that resemble Wilson disease, and studied long-term outcomes of existing treatments. These developments can be expected to have an immediate as well as a long-term impact on the clinical management of the disease, and point to promising avenues for future research.

Management of Wilson Disease Diagnosed in Infancy: An Appraisal of Available Experience to Generate Discussion

Increased access to molecular genetic testing is changing the demographics for diagnosing inherited disorders and imposing new challenges for medical management. Wilson disease (WD), typically diagnosed in older children and adults, can now be detected in utero and in infants (children younger than 24 months, including neonates) via genetic testing. An evidence-based approach to management of these neonates and extremely young children, who are typically asymptomatic, has been hampered by lack of clinical experience. We present a case of an infantile diagnosis of WD, review available experience, and discuss current trends in antenatal genetic testing of parents and fetus that may lead to a very early diagnosis of WD. Based on physiological and nutritional considerations, we propose an algorithmic approach to management of infantile WD as a starting point for further discussion. Future collaboration amongst specialists is essential to identify evidence-based approaches and best practice for managing treatment of infants with genetically diagnosed WD.

Reference intervals of spot urine copper excretion in preschool children and potential application in pre-symptomatic screening of Wilson disease

The objectives were to determine the reference intervals of spot urine copper excretion indexes in pre-school children and to evaluate their utility in screening for Wilson disease (WD). With spot urine collected from a control sample of preschool children (aged 3-7 years, n=153), the reference intervals of spot urine copper excretion indexes and their biological variation were defined. In order to investigate their utility performance in screening for WD in this age group, multiple spot urine samples from six WD patients who were diagnosed at presymptomatic stage were also analysed and compared. Cut-off values useful for detection of WD were defined by receiver operator curve (ROC) analysis. Biological (inter-individual) variation of spot urine copper indexes expressed as coefficient of variation (CVg) were around 60% at this age group, which was moderate and similar to other clinically useful urine tests, such as urine albumin excretion ratio. Spot urine copper excretion strongly correlated with both urine creatinine and osmolality. Linear regression against both creatinine and osmolality showed that ∼94% of data points in healthy preschool children fell within the prediction interval, suggesting that both were useful normalisation factors. ROC showed that copper to osmolality ratio was the best index with an area under curve (AUC) greater than 0.98. Cut-off values of 0.5 μmol/L, 0.1 μmol/mmol and 0.00085 μmol/mOsmol (32 μg/L, 56 μg/g creatinine and 0.054 μg/mOsmol, respectively, in conventional units) for spot urine copper concentration, copper to creatinine ratio and copper to osmolality ratio, respectively, have potential application in the differentiation of WD patients. Based on the data, a new WD screening strategy targeting preschool children is proposed. Application of a bivariate screening strategy using spot urine copper concentration and urine osmolality may be useful in a population-wide screening program for WD among preschool children.

Clinical features and mutational analysis in 114 young children with Wilson disease from South China

Wilson disease (WD) is a rare autosomal recessive disorder caused by mutations in the ATP7B gene. Clinical features and mutational analysis of Chinese children with WD at early age were rarely described. Herein, we retrospectively examined 114 children with WD at the mean of 5.9 years old age at diagnosis. Eight patients developed acute liver failure at mean age of 9.7 years old, 4 of whom died. Among the 114 patients, 86.0% were presymptomatic with isolated elevation of transaminases at diagnosis, 99.1% had decreased ceruloplasmin, and 68.4% had urinary copper excretion over 100 μg/24 hr. Bi-allele pathogenic ATP7B mutations were identified in all patients. Among the 60 mutations detected, 10 were novel, including 7 missense mutations (p.I566N, p.T704I, p.C980F, p.G1030 V, p.A1096Q, p.L1327P, and p.L1373F), 1 nonsense mutation (p.K866X), 1 small insertion (p.Y44LfsX2), and 1 small deletion (p.R1118PfsX10). The most frequent mutations were p.R778L, p.P992L, and p.I1148T, which affected 27.2, 25.4, and 20.2% of the 114 WD children, respectively. The patients carrying p.R778L presented a higher rate of acute liver failure than the patients without p.R778L (9.7% vs. 4.8%). These results will be helpful in establishing early diagnosis of WD at the gene level, offering beneficial information for genetic counseling and providing clues to genotype/phenotype correlation of ATP7B mutations.

Genetic analysis of ATP7B in 102 south Indian families with Wilson disease

Wilson disease (WD) is an autosomal recessive disorder, characterized by excessive deposition of copper in various parts of the body, mainly in the liver and brain. It is caused by mutations in ATP7B. We report here the genetic analysis of 102 WD families from a south Indian population. Thirty-six different ATP7B mutations, including 13 novel ones [p.Ala58fs*19, p.Lys74fs*9, p.Gln281*, p.Pro350fs*12, p.Ser481*, p.Leu735Arg, p.Val752Gly, p.Asn812fs*2, p.Val845Ala, p.His889Pro, p.Ile1184fs*1, p.Val1307Glu and p.Ala1339Pro], were identified in 76/102 families. Interestingly, the mutation analysis of affected individuals in two families identified two different homozygous mutations in each family, and thus each affected individual from these families harbored two mutations in each ATP7B allele. Of 36 mutations, 28 were missense, thus making them the most prevalent mutations identified in the present study. Nonsense, insertion and deletion represented 3/36, 2/36 and 3/36 mutations, respectively. The haplotype analysis suggested founder effects for all the 14 recurrent mutations. Our study thus expands the mutational landscape of ATP7B with a total number of 758 mutations. The mutations identified during the present study will facilitate carrier and pre-symptomatic detection, and prenatal genetic diagnosis in affected families.

Whole-exome sequencing identifies novel pathogenic variants across the ATP7B gene and some modifiers of Wilson's disease phenotype

BACKGROUND & AIMS

Wilson's disease (WD) is an autosomal recessive disorder associated with disease-causing alterations across the ATP7B gene, with highly variable symptoms and age of onset. We aimed to assess whether the clinical variability of WD relates to modifier genes.

METHODS

A total of 248 WD patients were included, of whom 148 were diagnosed after age of 17. Human exome libraries were constructed using AmpliSeq technology and sequenced using the IonProton platform.

RESULTS

ATP7B p.His1069Gln mutation was present in 215 patients, with 112 homozygotes and 103 heterozygotes. Three other mutations: p.Gln1351Ter, p.Trp779Ter and c.3402delC were identified in >10 patients. Among patients, 117 had a homozygous mutation, 101 were compound heterozygotes, 27 had one heterozygous mutation, and 3 other patients had no identifiable pathogenic variant of ATP7B. Sixteen mutations were novel, found as part of a compound mutation or as a sole, homozygous mutation. For disease phenotype prediction, age at diagnosis was a deciding factor, while frameshift allelic variants of ATP7B and being male increased the odds of developing a neurological phenotype. Rare allelic variants in ESD and INO80 increased and decreased chances for the neurological phenotype, respectively, while rare variants in APOE and MBD6 decreased the chances of WD early manifestation. Compound mutations contributed to earlier age of onset.

CONCLUSIONS

In a Polish population, genetic screening for WD may help genotype for four variants (p.His1069Gln, p.Gln1351Ter, p.Trp779Ter and c.3402delC), with direct sequencing of all ATP7B amplicons as a second diagnostic step. We also identified some allelic variants that may modify a WD phenotype.

Update on the Diagnosis and Management of Wilson Disease

PURPOSE OF REVIEW

Exciting developments relating to Wilson disease (WD) have taken place with respect to both basic biological and clinical research. This review critically examines some of these findings and considers their implications for current thinking about WD. It is not a comprehensive review of WD as a clinical disorder.

RECENT FINDINGS

The structure of the gene product of ATP7B, abnormal in WD, is being worked out in detail, along with a broader description of how the protein ATP7B (Wilson ATPase) functions in cells including enterocytes, not only in relation to copper disposition but also to lipid synthesis. Recent population studies raise the possibility that WD displays incomplete penetrance. Innovative screening techniques may increase ascertainment. New strategies for diagnosing and treating WD are being developed. Several disorders have been identified which might qualify as WD-mimics. WD can be difficult to diagnose and treat. Insights from its pathobiology are providing new options for managing WD.

Functional Characterization of Novel ATP7B Variants for Diagnosis of Wilson Disease

Background: Diagnosis of rare Wilson disease (WD) in pediatric patients is difficult, in particular when hepatic manifestation is absent. Genetic analysis of ATP7B represents the single major determinant of the diagnostic scoring system in WD children having mild symptoms. Objectives: To assess the impact of molecularly expressed ATP7B gene products in order to assist diagnosis of Wilson disease in pediatric patients having a novel mutation and subtle neuropsychiatric disease. Methods: The medical history, clinical presentation, biochemical parameters, and the genetic analysis of ATP7B were determined. Due to ambiguous clinical and biochemical findings and identification of a novel compound ATP7B mutation with unknown disease-causing status, a molecular analysis of the ATP7B gene products in a previously well characterized cell model was performed. Results: The ATP7B variants were transgenically expressed and the respective gene function molecularly characterized. Despite normal mRNA expression, low ATP7B protein expression of the mutants p.L168P and p.S1423N was observed (34.3 ± 8% and 66.0 ± 8%, respectively). Copper exposure did not result in decreased viability of transgenic cells as compared to wild type. Intracellular copper accumulation was reduced (≤47.9 ± 8%) and intracellular protein trafficking was impaired. Conclusion: Our report suggests that functional characterization of novel ATP7B mutants can assist diagnosis; however mild functional impairments of ATP7B variants may hamper the value of such approaches.