A genetic study of Wilson's disease in the United Kingdom

Research progress in stem cell therapy for Wilson disease

Wilson disease (WD), also known as hepatolenticular degeneration, is an autosomal recessive disorder characterized by disorganized copper metabolism caused by mutations in the ATP7B gene. Currently, the main treatment options for WD involve medications such as d-penicillamine, trientine hydrochloride, zinc acetate, and liver transplantation. However, there are challenges that encompass issues of poor compliance, adverse effects, and limited availability of liver sources that persist. Stem cell therapy for WD is currently a promising area of research. Due to the advancement in stem cell directed differentiation technology in vitro and the availability of sufficient stem cell donors, it is expected to be a potential treatment option for the permanent correction of abnormal copper metabolism. This article discusses the research progress of stem cell therapy for WD from various sources, as well as the challenges and future prospects of the clinical application of stem cell therapy for WD.

Phenotype and molecular characterization of Wilson's disease in Morocco

BACKGROUND AND STUDY AIMS

In Morocco the prevalence of Wilson disease (WD) and the spectrum of mutations are not known. The aim of the present study was to estimate the prevalence of WD in Morocco, to evaluate the phenotype among a large cohort of WD patients, and to characterize ATP7B variants in a subgroup of WD patients.

PATIENTS AND METHODS

We collected data from 226 patients admitted to five university hospital centers in Morocco between 2008 and 2020. The diagnosis was based on clinical manifestations, function tests and biochemical parameters. The genotype was characterized in 18 families diagnosed at the University Hospital Center of Marrakesh, by next generation sequencing.

RESULTS

The mean annual prevalence in Morocco was 3.88 per 100,000 and the allele frequency was 0.15 %. Among the 226 patients included (121 males and 105 females), 196 were referred for a hepatic or neurological involvement and 30 were asymptomatic. The mean age at diagnosis was 13 ± 5.1 years (range: 5 - 42 years). Consanguinity was found in 63.3 % of patients. The mean duration of illness was 2.8 ± 1.9 years. Kayser-Fleischer rings were found in 131 (67.9 %) of 193 patients. Among the 196 symptomatic patients, 141/159 (88.7 %) had low serum ceruloplasmin (<0.2 g/L) and a high 24-hours urinary copper (>100 μg/day) was found in 173/182 (95.1 %) patients. The initial treatment was D-penicillamine in 207 patients, zinc acetate in five, zinc sulfate in five, and nine patients were not treated; 60/207 (29 %) patients have stopped treatment. A total of 72 patients died; the mortality rate was 31.9 %. Eight different ATP7B variants were identified among the 18 patients studied, of which two were novel (p.Cys1104Arg and p.Gln1277Hisfs*52), and six previously published (p.Gln289Ter, p.Cys305Ter, p.Thr1232Pro, p.Lys1020Arg, p.Glu583ArgfsTer25 and c.51+4A>T). All informative patients were homozygous for the disease-causing mutation.

CONCLUSION

In Morocco, a high prevalence due to consanguinity and a high mortality rate due to the difficulty of diagnosis and lack of treatment were observed in WD patients. NGS sequencing identified new ATP7B variants in WD patients from Morocco.

Structure and mechanism of the human copper transporting ATPases: Fitting the pieces into a moving puzzle

Human copper transporters ATP7B and ATP7A deliver copper to biosynthetic pathways and maintain copper homeostasis in the cell. These enzymes combine several challenges for structural biology because they are large low abundance membrane proteins with many highly mobile domains and long disordered loops. No method has yet succeeded in solving the structure of the complete fully functional protein. Still, X-ray crystallography, Cryo-EM and NMR helped to piece together a structure based model of the enzyme activity and regulation by copper. We review the structures of ATP7B and ATP7A with an emphasis on the mechanistic insights into the unique aspects of the transport function and regulation of the human copper ATPases that have emerged from more than twenty years of research.

Genetics of liver disease in adults

Chronic liver disease stands as a significant global health problem with an estimated 2 million annual deaths across the globe. Combining the use of next-generation sequencing technologies with evolving knowledge in the interpretation of genetic variation across the human genome is propelling our understanding, diagnosis, and management of both rare and common liver diseases. Here, we review the contribution of risk and protective alleles to common forms of liver disease, the rising number of monogenic diseases affecting the liver, and the role of somatic genetic variants in the onset and progression of oncological and non-oncological liver diseases. The incorporation of genomic information in the diagnosis and management of patients with liver disease is driving the beginning of a new era of genomics-informed clinical hepatology practice, facilitating personalized medicine, and improving patient care.

Self-Control Training: A Scoping Review

We conducted a scoping review of the behavior analytic self-control training (SCT) literature. To identify included articles, we searched key terms in six databases for articles published between 1988 and 2021. We included empirical articles that used a behavioral approach to self-control training with human participants for whom increasing self-control choice was a clinically significant goal and measured self-control and impulsive choice as dependent variables. Twenty-five experiments from 24 articles with a total of 79 participants were included in the review. This review aims to summarize the characteristics of SCT procedures and outcomes, provide recommendations for future research directions, and offer practical suggestions to clinicians incorporating SCT into practice. We examined similarities across studies regarding the independent variables manipulated in SCT, dependent variables measured, metrics of successful interventions, and assessment of generalization and maintenance of self-control choice. Twenty-one experiments arranged concurrent self-control- and impulsive-choice options with positive reinforcement, and four experiments arranged self-control training with negative-reinforcement contingencies. Variations of SCT included progressively increasing delays, intervening activities, signaled delays, antecedent rules, and commitment responses. Providing an intervening activity during the delay was largely successful at increasing self-control choice. Maintenance and generalization of increased self-control choice were assessed in two and three experiments, respectively. Future research should focus on improving the generality of SCT procedures in clinical settings by increasing terminal delays, fading out intervening activities, including probabilistic outcomes, and combining appetitive and aversive outcomes.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40617-023-00885-y.

Identification of lncRNA-miRNA-mRNA Networks in the Lenticular Nucleus Region of the Brain Contributes to Hepatolenticular Degeneration Pathogenesis and Therapy

Long non-coding RNAs (lncRNAs) are a recently discovered group of non-coding RNAs that play a crucial role in the regulation of various human diseases, especially in the study of nervous system diseases which has garnered significant attention. However, there is limited knowledge on the identification and function of lncRNAs in hepatolenticular degeneration (HLD). The objective of this study was to identify novel lncRNAs and determine their involvement in the networks associated with HLD. We conducted a comprehensive analysis of RNA sequencing (RNA-seq) data, reverse transcription-quantitative polymerase chain reaction (RT-qPCR), and computational biology to identify novel lncRNAs and explore their potential mechanisms in HLD. We identified 212 differently expressed lncRNAs, with 98 upregulated and 114 downregulated. Additionally, 32 differently expressed mRNAs were found, with 15 upregulated and 17 downregulated. We obtained a total of 1131 pairs of co-expressed lncRNAs and mRNAs by Pearson correlation test and prediction and annotation of the lncRNA-targeted miRNA-mRNA network. The differential lncRNAs identified in this study were found to be involved in various biological functions and signaling pathways. These include translational initiation, motor learning, locomotors behavior, dioxygenase activity, integral component of postsynaptic membrane, neuroactive ligand-receptor interaction, nuclear factor-kappa B (NF-κB) signaling pathway, cholinergic synapse, sphingolipid signaling pathway, and Parkinson's disease signaling pathway, as revealed by the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses. Six lncRNAs, including XR_001782921.1 (P < 0.01), XR_ 001780581.1 (P < 0.01), ENSMUST_00000207119 (P < 0.01), XR_865512.2 (P < 0.01), TCONS_00005916 (P < 0.01), and TCONS_00020683 (P < 0.01), showed significant differences in expression levels between the model group and normal group by RT-qPCR. Among these, four lncRNAs (TCONS_00020683, XR_865512.2, XR_001780581.1, and ENSMUST00000207119) displayed a high degree of conservation. This study provides a unique perspective for the pathogenesis and therapy of HLD by constructing the lncRNA-miRNA-mRNA network. This insight provides a foundation for future exploration in this field.

Epidemiology of Wilson's Disease and Pathogenic Variants of the ATP7B Gene Leading to Diversified Protein Disfunctions

Wilson's disease (WD) is an autosomal recessive disorder characterized by toxic accumulation of copper in the liver, brain, and other organs. The disease is caused by pathogenic variants in the ATP7B gene, which encodes a P-type copper transport ATPase. Diagnosing WD is associated with numerous difficulties due to the wide range of clinical manifestations and its unknown dependence on the physiological characteristics of the patient. This leads to a delay in the start of therapy and the subsequent deterioration of the patient's condition. However, in recent years, molecular genetic testing of patients using next generation sequencing (NGS) has been gaining popularity. This immediately affected the detection speed of WD. If, previously, the frequency of this disease was estimated at 1:35,000-45,000 people, now, when conducting large molecular genetic studies, the frequency is calculated as 1:7026 people. This certainly points to the problem of identifying WD patients. This review provides an update on the performance of epidemiological studies of WD and describes normal physiological functions of the protein and diversified disfunctions depending on pathogenic variants of the ATP7B gene. Future prospects in the development of WD genetic diagnostics are also discussed.

The potential serum sphingolipid biomarkers for distinguishing Wilson disease

BACKGROUND

The diagnosis of Wilson's disease (WD) remains a challenging endeavor in clinical practice. Serum sphingolipids play a significant role in the development of liver disease. In this study, we examined the serum sphingolipid profile in patients with WD and explored the potential diagnostic utility of serum sphingolipid metabolites. These metabolites may aid in distinguishing WD patients from healthy controls and identifying those with a risk of cirrhosis.

METHODS

This study consecutively enrolled 26 WD patients and 88 healthy controls. We utilized high-performance liquid chromatography-tandem mass spectrometry to analyze a panel of 88 serum sphingolipid metabolites. The data were analyzed by multivariate statistical methods.

RESULTS

Among the 88 sphingolipids metabolites analyzed, 17 sphingolipids were observed significant differences between WD and HC groups (all P < 0.05). Notably, five sphingolipids, namely S1P (d18:1), Cer (d18:2/21:0), SM41:2, sph(d18:1), and Cer (d18:2/22:0), each with an AUC exceeding 0.9, emerged as potential biomarkers for WD. Additionally, in the comparison between WD patients with and without cirrhosis, 24 sphingolipid metabolites exhibited significant differences (all P < 0.05). We identified Cer(d18:1/20:0), Cer(d18:2/22:0), Cer(d18:2/24:0), Cer(d18:2/20:0), and Cer(d18:2/18:0), each with an AUC exceeding 0.9, as potential serological markers for WD patients with cirrhosis.

CONCLUSION

For enhanced clinical applicability, we propose considering Cer (d18:2/22:0) as a predictive marker applicable to both WD patients and their susceptibility to cirrhosis. This particular ceramide has exhibited strong diagnostic and predictive performance. These findings have the potential to facilitate non-invasive WD diagnosis.

Changes in Hepatic Function After Splenectomy for Hepatolenticular Degeneration, Cirrhosis, and Hypersplenism

BACKGROUND

Patients with hepatic reticulum degeneration (HLD) may eventually develop complications of cirrhosis with splenomegaly and hypersplenism, requiring splenectomy to alleviate hypersplenism and complete lifelong copper therapy. The purpose of this study is to investigate the effect of splenectomy on liver function in patients with hypersplenism.

METHODS

A retrospective systematic analysis was conducted on the liver function indicators of 220 HLD patients who underwent splenectomy from January 2015 to January 2018 before surgery and on days 1, 3, 5, 7, and 14 after surgery. Among them, 30 patients were followed up for 6 months.

RESULTS

The Child score increased on the 1st day after surgery and gradually decreased after the 1st day. The level of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and total bilirubin (TB) increased 5 days after surgery (P < .01) and decreased on the 14th day after surgery (P < .01); the level of albumin (ALB) decreased on the 1st, 3rd, and 5th day after surgery (P < .01) and increased on the 14th day (P < .01). The follow-up results of the patient for 6 months showed that the levels of ALT and AST decreased, while the levels of ALB increased 6 months after surgery.

CONCLUSION

Splenectomy is proved to be beneficial for the improvement of liver function in HLD patients combined with hypersplenism, which realize a lifelong anti-copper treatment.

Recent advances in the diagnosis and management of Wilson's disease

In this editorial, the reader will be updated on novel epidemiological, diagnostic, and therapeutical proposals in the field of Wilson disease.

Hepatitis B virus infection in patients with Wilson disease: A large retrospective study

BACKGROUND

Wilson disease (WD) is the most common genetic metabolic liver disease. Some studies have shown that comorbidities may have important effects on WD. Data on hepatitis B virus (HBV) infection in patients with WD are limited.

AIM

To investigate the prevalence and clinical impact of HBV infection in patients with WD.

METHODS

The clinical data of patients with WD were analyzed retrospectively, and the data of patients with concurrent WD and HBV infection were compared with those of patients with isolated WD.

RESULTS

Among a total of 915 WD patients recruited, the total prevalence of current and previous HBV infection was 2.1% [95% confidence interval (CI): 1.2%-3.0%] and 9.2% (95%CI: 7.3%-11.1%), respectively. The main finding of this study was the identification of 19 patients with concurrent WD and chronic hepatitis B (CHB) infection. The diagnosis of WD was missed in all but two patients with CHB infection. The mean delay in the diagnosis of WD in patients with concurrent WD and CHB infection was 32.5 mo, which was significantly longer than that in patients with isolated WD (10.5 mo). The rates of severe liver disease and mortality in patients with concurrent WD and CHB infection were significantly higher than those in patients with isolated WD (63.1% vs 19.3%, P = 0.000 and 36.8% vs 4.1%, P < 0.001, respectively). Binary logistic regression analysis revealed a significantly higher risk of severe liver disease at the diagnosis of WD in patients with current HBV infection [odds ratio (OR) = 7.748; 95%CI: 2.890-20.774; P = 0.000)] or previous HBV infection (OR = 5.525; 95%CI: 3.159-8.739; P = 0.000) than in patients with isolated WD.

CONCLUSION

The total prevalence of current HBV infection in patients with WD was 2.1%. The diagnosis of WD in CHB patients is usually missed. HBV infection is an independent risk factor for severe liver disease in WD patients. The diagnosis of WD should be ruled out in some patients with CHB infection.

A paradigm shift in non-viral liver cirrhosis: a multicenter study on clinicoepidemiological characteristics and outcome of non-B non-C cirrhosis

Background

Chronic hepatitis C (HCV) and B viruses (HBV) represent the commonest global causes of liver cirrhosis. Other etiologies of non-viral cirrhosis such as autoimmune, metabolic, vascular, or biliary diseases are underestimated. The study aimed to identify causes, clinicoepidemiological characteristics, and outcome of non-B non-C liver cirrhosis. This Egyptian multicenter study recruited patients with liver cirrhosis excluding HCV and HBV. Clinical evaluation and the mortality were recorded. Laboratory, radiological, and histopathological assessment to diagnose the etiology was performed.

Results

One hundred eighty-eight patients were included: 54.3% were males. Autoimmune hepatitis (AIH) was the most common cause of cirrhosis (28.2%), followed by Budd-Chiari syndrome (BCS) in 25%, and cryptogenic in 23.9%. Metabolic causes such as Wilson’s disease, non-alcoholic steatohepatitis (NASH), and hemochromatosis were reported in 7.4%, 3.2%, and 1.1%, respectively. Biliary and cardiac cirrhosis were less frequent. Older age was prevalent in hemochromatosis (67.5 ± 17.7 years) and NASH (60.7 ± 11), while young age in Wilson’s disease (29.5 ± 14.8) and secondary biliary cirrhosis (14.8 ± 4.8). Rural residence was common (60.6%). Mortality was reported in BCS (40.4%), cryptogenic (28.9%), cardiac (25%), Wilson’s disease (21.4%), AIH (17%), and NASH (16.7%). Hepatocellular carcinoma complicated 10.6% of cases. A significantly high percentage of patients had decompensated cirrhosis. Child–Pugh class and rural residence were significant predictors of mortality.

Conclusion

This first report on non-B non-C cirrhosis in Egypt revealed a high prevalence of AIH, BCS, and cryptogenic cirrhosis. Advanced Child class and rural residence were the predictors of mortality.

Liver disease in adolescents

In this article, we discuss common liver diseases in the adolescent population. We describe the initial evaluation of an adolescent presenting with new-onset liver enzyme abnormalities, based on the clinical history and physical examination. The management approach to the adolescent with liver disease is exemplified, including monitoring for adherence, risk-taking behaviours and focusing on psychosocial aspects of their care. Finally, we highlight the challenges of caring for the adolescent patient and the importance of addressing not only the liver disease but, more importantly, the holistic approach towards their management.

Wilson disease: a summary of the updated AASLD Practice Guidance

Wilson disease (WD) is caused by autosomal variants affecting the ATP7B gene on chromosome 13, resulting in alterations in physiological copper homeostasis and copper accumulation. Excess copper clinically manifests in many organs, most often in the central nervous system and liver, ultimately causing cirrhosis and death. Often considered a pediatric or young adult disease, WD actually affects patients of all ages, and aging patients need to be regularly managed with long-term follow-up. Despite over a century of advances in diagnosis and treatment, WD is still associated with diagnostic challenges and considerable disability and death, in part due to delays in diagnosis and limitations in treatment. Standard-of-care treatments are considered generally effective when the diagnosis is timely but are also limited by efficacy, safety concerns, multiple daily dosing, and adherence. This expert perspective review seeks to facilitate improvements in the awareness, understanding, diagnosis, and management of WD. The objectives are to provide a full overview of WD and streamline updated diagnosis and treatment guidance, as recently published by the American Association for the Study of Liver Diseases, in a practical way for clinical use.

Psychosocial Basis of Human Sufferings and Poverty in Patients with Neurological and Psychiatric Disorders

Neurological disorders and psychiatric ailments often lead to cognitive disabilities and low attainment of education, pivoting misconceptions, myths, and misbeliefs. Poverty and low educational attainment are intriguingly associated with poor awareness and perception of these diseases that add to the suffering. Poverty goes parallel with a low level of education and is intricately associated with neuropsychiatric ailments, which have the potential to spread transgenerationally. Robust education policies, proper government rules and regulations against the spread of disease-related myths and misconceptions, uplifting medical education in its true sense, voices against consanguinity, and programs to raise scientific perception about diseases can help to throw light at the end of this dark tunnel. In this article, the authors intend to 1) decipher the potential psychosocial basis of human suffering and poverty in patients with neurological and psychiatric disorders, and 2) discuss the apropos way-outs that would potentially mitigate suffering, and alleviate the economic burden and cognitive disabilities of families with neuropsychiatric diseases.

Clinical spectrum and genotype-phenotype associations in Finnish patients with Wilson's disease

Genotype-phenotype correlation data covering all ages of Wilson's disease onset in Caucasian patients are limited. We therefore analyzed genotype-phenotype correlations in a retrospective cohort of Finnish patients. Six homozygous (HoZ) and 11 compound heterozygous (CoHZ) patients were included. There were no differences in the presence/absence of hepatic, neurological, psychiatric or any symptoms at diagnosis (p > 0.30 for all) between HoZ and CoHZ patients, but HoZ patients had an earlier age of diagnosis (median 6.7 versus 34.5; p = 0.003). Severe liver affliction was almost exclusively associated with the p.H1069Q variant. Patients with p.H1069Q had a later mean age of diagnosis (30.2 ± 11.6 vs. 8.7 ± 4.9 years; p < 0.001) compared to those without. There were no differences in the presence/absence of hepatic, neurological, psychiatric or any symptoms at diagnosis between p.H1069Q-positive and p.H1069Q-negative patients (p > 0.54 for all). These results suggest that population-specific factors may partly explain the high clinical variability of Wilson's disease.

Addressing the Challenges in the Diagnosis and Management of Pediatric Wilson's Disease-Case Report and Literature Review

Wilson's disease (WD) is an autosomal recessive disorder, in which the metabolism of copper is affected by metal accumulation in several organs that causes gradual organ degeneration. Since Wilson's initial description of WD over a century ago, there have been significant improvements in understanding and managing the condition. Nevertheless, the ongoing gap between the onset of symptoms and diagnosis highlights the difficulties in identifying this copper overload disorder early. Despite being a treatable condition, detecting WD early remains a challenge for healthcare professionals at all levels of care, likely due to its rarity. The key challenge is, therefore, to educate physicians on how to identify atypical or infrequent symptoms of WD, prompting them to consider the diagnosis more carefully. The purpose of our review is to draw attention to the difficulties associated with diagnosing pediatric WD, starting from our personal experience of a complex case and then examining relevant literature. In summary, the diagnosis of WD in children is intricate and requires a heightened level of suspicion to identify this infrequent condition. A thorough evaluation by a multidisciplinary team of physicians, along with genetic testing, histopathologic examination, and specialized imaging studies, may be necessary to confirm the diagnosis and guide treatment.

Wilson's disease: best practice

Wilson's disease is an autosomal recessive disorder arising from pathogenic variants in the Atp7b gene on chromosome 13. The defective translated ATPase copper (Cu) transport protein produced leads to Cu accumulation, initially affecting the liver but eventually affecting other cells. It is just over 20 years since the last Best Practice on this topic in this journal. This review is an update on this, covering new disease biomarkers, pathogenesis, assumptions around clinical features and developments in therapy.

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.

Genomic Variations in ATP7B Gene in Indian Patients with Wilson Disease

OBJECTIVE

To report genotype data of the patients with Wilson disease (WD) hailing from across several parts of India to add to the available spectrum of causative variants in ATP7B gene (ATPase copper transporting beta polypeptide gene) and associated phenotypes in the Indian population.

METHODS

The entire ATP7B gene was sequenced in 58 patients with WD and additional testing was also done by MLPA to look for intragenic deletions duplications and exome sequencing to rule out genetic variations with similar phenotypic overlap.

RESULTS

Of all patients, 37 patients had a total of 33 distinct pathogenic variations, including 29 in the exonic regions and 4 at intronic splice sites. Of the variations identified, six were novel. The underlying genomic variations could be identified in nearly two-thirds of the patients by sequencing the entire gene.

CONCLUSIONS

This study reports the genotype-phenotype data to add to the available spectrum of causative variants in ATP7B gene. The inability to detect a pathogenic variation in some patients and the existence of phenotypic variations in individuals with the same variation suggest that additional factors or genes may play a role in causation of the disease. Further, a marked genetic heterogeneity was found in the study patients, indicating ethnic diversity of the Indian population.

Missing heritability of Wilson disease: a search for the uncharacterized mutations

Wilson disease (WD), a copper metabolism disorder caused by mutations in ATP7B, manifests heterogeneous clinical features. Interestingly, in a fraction of clinically diagnosed WD patients, mutations in ATP7B appears to be missing. In this review we discuss the plausible explanations of this missing heritability and propose a workflow that can identify the hidden mutations. Mutation analyses of WD generally includes targeted sequencing of ATP7B exons, exon-intron boundaries, and rarely, the proximal promoter region. We propose that variants in the distal cis-regulatory elements and/or deep intronic variants that impact splicing might well represent the hidden mutations. Heterozygous del/ins that remain refractory to conventional PCR-sequencing method may also represent such mutations. In this review, we also hypothesize that mutations in the key copper metabolism genes, like, ATOX1, COMMD1, and SLC31A1, could possibly lead to a WD-like phenotype. In fact, WD does present overlapping symptoms with other rare genetic disorders; hence, the possibility of a misdiagnosis and thus adding to missing heritability cannot be excluded. In this regard, it seems that whole-genome analysis will provide a comprehensive and rapid molecular diagnosis of WD. However, considering the associated cost for such a strategy, we propose an alternative customized screening schema of WD which include targeted sequencing of ATP7B locus as well as other key copper metabolism genes. Success of such a schema has been tested in a pilot study.

A Century of Progress on Wilson Disease and the Enduring Challenges of Genetics, Diagnosis, and Treatment

Wilson disease (WD) is a rare, inherited metabolic disorder manifested with varying clinical presentations including hepatic, neurological, psychiatric, and ophthalmological features, often in combination. Causative mutations in the ATP7B gene result in copper accumulation in hepatocytes and/or neurons, but clinical diagnosis remains challenging. Diagnosis is complicated by mild, non-specific presentations, mutations exerting no clear effect on protein function, and inconclusive laboratory tests, particularly regarding serum ceruloplasmin levels. As early diagnosis and effective treatment are crucial to prevent progressive damage, we report here on the establishment of a global collaboration of researchers, clinicians, and patient advocacy groups to identify and address the outstanding challenges posed by WD.

Diagnosis and Outcomes of Late-Onset Wilson's Disease: A National Registry-Based Study

BACKGROUND

Wilson's disease (WD) is usually diagnosed in children and young adults; limited data exist on late-onset forms.

OBJECTIVE

The aim was to characterize the clinical and paraclinical presentations, therapeutic management, and outcomes in patients with late-onset WD.

METHODS

Patients diagnosed with WD after age 40 years were identified from the French Wilson's Disease Registry (FWDR). Clinical, laboratory, and imaging findings and treatment were reported at diagnosis and last follow-up.

RESULTS

Forty-five patients were identified (median age: 49, range: 40-64) and placed in three groups according to their clinical presentation: neurological (n = 20, median diagnostic delay: 20 months), hepatic (n = 13, diagnostic delay: 12 months), and family screening (n = 12), all confirmed genetically. Six neurological patients had an atypical presentation (1 torticollis, 2 writer's cramps, 2 functional movement disorders, and 1 isolated dysarthria), without T2/fluid-attenuated inversion recovery brain magnetic resonance imaging (MRI) hyperintensities; 5 of 6 had no Kayser-Fleischer ring (KFR); 5 of 6 had liver involvement. In the neurological group, 84% of patients improved clinically, and 1 developed copper deficiency. In the hepatic group, 77% had cirrhosis; 6 patients required liver transplantation. In the screened group, 43% had mild liver involvement; 3 were not treated and remained stable; 24-h urinary copper excretion was normal in 33% of patients at diagnosis.

CONCLUSIONS

In the FWDR, late-onset forms of WD affect 8% of patients, mostly with neurological presentations. Thirty percent of the neurological forms were atypical (isolated long-lasting symptoms, inconspicuous brain MRI, no KFR). With personalized treatment, prognosis was good. This study emphasized that WD should be suspected at any age and even in cases of atypical presentation. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Allelic prevalence and geographic distribution of cerebrotendinous xanthomatosis

BACKGROUND

Cerebrotendinous xanthomatosis (CTX) is a rare recessive genetic disease characterized by disruption of bile acid synthesis due to inactivation of the CYP27A1 gene. Treatment is available in the form of bile acid replacement. CTX is likely underdiagnosed, and prevalence estimates based on case diagnosis are probably inaccurate. Large population-based genomic databases are a valuable resource to estimate prevalence of rare recessive diseases as an orthogonal unbiased approach building upon traditional epidemiological studies.

METHODS

We leveraged the Hardy-Weinberg principle and allele frequencies from gnomAD to calculate CTX prevalence. ClinVar and HGMD were used to identify high-confidence pathogenic missense variants and to calculate a disease-specific cutoff. Variant pathogenicity was also assessed by the VarSome implementation of the ACMG/AMP algorithm and the REVEL in silico predictor.

RESULTS

CTX prevalence estimates were highest in Asians (1:44,407-93,084) and lowest in the Finnish population (1:3,388,767). Intermediate estimates were found in Europeans, Americans, and Africans/African Americans (1:70,795-233,597). The REVEL-predicted pathogenic variants accounted for a greater increase in prevalence estimates for Europeans, Americans, and Africans/African Americans compared with Asians. We identified the most frequent alleles designated pathogenic in ClinVar (p.Gly472Ala, p.Arg395Cys), labeled pathogenic based on sequence consequence (p.Met1?), and predicted to be pathogenic by REVEL (p.Met383Lys, p.Arg448His) across populations. Also, we provide a prospective geographic map of estimated disease distribution based on CYP27A1 variation queries performed by healthcare providers from selected specialties.

CONCLUSIONS

Prevalence estimates calculated herein support and expand upon existing evidence indicating underdiagnosis of CTX, suggesting that improved detection strategies are needed. Increased awareness of CTX is important for early diagnosis, which is essential for patients as early treatment significantly slows or prevents disease progression.

Wilson Disease and Alpha1-Antitrypsin Deficiency: A Review of Non-Invasive Diagnostic Tests

Wilson disease and alpha1-antitrypsin deficiency are two rare genetic diseases that may impact predominantly the liver and/or the brain, and the liver and/or the lung, respectively. The early diagnosis of these diseases is important in order to initiate a specific treatment, when available, ideally before irreversible organ damage, but also to initiate family screening. This review focuses on the non-invasive diagnostic tests available for clinicians in both diseases. These tests are crucial at diagnosis to reduce the potential diagnostic delay and assess organ involvement. They also play a pivotal role during follow-up to monitor disease progression and evaluate treatment efficacy of current or emerging therapies.

Prevalence of celiac disease in patients with liver diseases: a systematic review and meta-analyses

OBJECTIVES

A subset of patients with celiac disease (CeD) have liver involvement in the form of hypertransaminasemia, liver cirrhosis and autoimmune hepatitis. We conducted a systematic review with meta-analyses to determine pooled prevalence of CeD in patients with cryptogenic cirrhosis, all-cause cirrhosis, cryptogenic hypertransaminasemia, and all-cause hypertransaminasemia.

METHODS

We searched PubMed and EMBASE up to January 2022. Cross-sectional, case-control and prospective cohort studies performing serological tests and/or intestinal biopsy for CeD on patients with cryptogenic cirrhosis, all-cause cirrhosis, cryptogenic hypertransaminasemia and all-cause hypertransaminasemia were included, to calculate pooled estimates of seroprevalence and prevalence of biopsy-confirmed CeD in these four groups.

RESULTS

Of 6,871 articles screened, 20 articles were included finally in three meta-analyses for cryptogenic cirrhosis, all-cause cirrhosis and cryptogenic hypertransaminasemia. For the all-cause hypertransaminasemia group, a qualitative review of four studies was done instead of a meta-analysis, due to significant differences in studies. The pooled prevalence (95%CI) of biopsy-confirmed CeD, in cryptogenic cirrhosis was 4.6%(2.2-7.5%) while pooled prevalence of biopsy-confirmed CeD in all-cause cirrhosis was 0.8%(0-3.4%). Pooled prevalence of biopsy-confirmed CeD in cryptogenic hypertransaminasemia was 5.7%(3.2-8.8%).

CONCLUSIONS

Nearly one in 20 patients each with cryptogenic cirrhosis and cryptogenic hypertransaminasemia have CeD, hence they should both be considered high-risk groups for CeD. While prevalence of CeD in all-cause cirrhosis is similar to that in general population, it may be worth screening them for CeD as liver pathology has potential for reversal in them.

The Role of Copper Homeostasis in Brain Disease

In the human body, copper is an important trace element and is a cofactor for several important enzymes involved in energy production, iron metabolism, neuropeptide activation, connective tissue synthesis, and neurotransmitter synthesis. Copper is also necessary for cellular processes, such as the regulation of intracellular signal transduction, catecholamine balance, myelination of neurons, and efficient synaptic transmission in the central nervous system. Copper is naturally present in some foods and is available as a dietary supplement. Only small amounts of copper are typically stored in the body and a large amount of copper is excreted through bile and urine. Given the critical role of copper in a breadth of cellular processes, local concentrations of copper and the cellular distribution of copper transporter proteins in the brain are important to maintain the steady state of the internal environment. The dysfunction of copper metabolism or regulatory pathways results in an imbalance in copper homeostasis in the brain, which can lead to a myriad of acute and chronic pathological effects on neurological function. It suggests a unique mechanism linking copper homeostasis and neuronal activation within the central nervous system. This article explores the relationship between impaired copper homeostasis and neuropathophysiological progress in brain diseases.

Design, Optimization and Validation of the ARMS PCR Protocol for the Rapid Diagnosis of Wilson's Disease Using a Panel of 14 Common Mutations for the European Population

BACKGROUND

Wilson's disease (WD) is an autosomal recessive inherited disorder of copper metabolism resulting from various mutations in the ATP7B gene. Despite good knowledge and successful treatment options, WD is a severe disease that leads to disability, destructively affecting the quality of life of patients. Currently, none of the available laboratory tests can be considered universal and specific for the diagnosis of WD. Therefore, the introduction of genetic diagnostic methods that allow for the identification of the root cause at any stage over the course of the disease gave hope for an earlier solution of diagnostic issues in patients with WD.

METHODS

A method for the genetic diagnosis of WD based on ARMS PCR, DreamTaq Green PCR Master Mix and modified primers has been developed. This method is able to detect 14 mutant alleles: p.His1069Gln, p.Glu1064Lys, p.Met769HisfsTer26, p.Gly710Ser, p.Ser744Pro, p.Ala1135GlnfsTer13, p.Arg778Leu, p.Arg1041Trp, p.Arg616Gln, p.Arg778Gly, p.Trp779*, p.Val834Asp, p.Gly943Ser and p.3222_3243+21del43.

RESULTS

The primers for all mutations were highly specific with an absence of wild-type amplification. All the results were validated by direct DNA Sanger sequencing.

CONCLUSIONS

This fast and economical method provides coverage for the identified common mutations, thereby making ARMS PCR analysis using DreamTaq Green PCR Master Mix and modified primers feasible and attractive for large-scale routine use.

Mutational analysis of exon 8 and exon 14 of ATP7B gene in Bangladeshi children with Wilson disease

BACKGROUND : Wilson disease (WD) is an autosomal recessive disorder caused by mutation in the Adenosine Triphosphate 7B (ATP7B) gene. The spectrum of ATP7B mutation varies in different populations. The objective of this study was to identify the mutation in exon 8 and exon 14 of ATP7B gene in Bangladeshi children clinically diagnosed as WD. We also aimed to explore the phenotypic presentation.

METHODS

It was a cross sectional observational study. The study was conducted at the Department of Paediatric Gastroenterology, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh from January 2017 to June 2018. A total of 37 patients diagnosed with WD were enrolled for the study. Venous blood (about 3 mL) was drawn aseptically from each patient into tube containing ethyline diamine tetraacetic acid (EDTA) and preserved at -30°C for long-term preservation. The peripheral blood leukocytes of the patients and genomic DNAs were extracted. Exons 14 and 8 of ATP7B and their associated splice-site junctions were amplified by the polymerase chain reaction (PCR). The size and quantity of PCR products were verified by electrophoresis in 1.5% (w/v) agarose gel. 74 (37 × 2) PCR products were sent for Sanger Sequencing. The sequences were analyzed by Chromas version 2.6.6 software and the nucleotide blast was done by National Center for Biotechnology Information (NCBI) nucleoblast. Finally, the sequences were analyzed using AB Applied Bio systems and were matched with the reference sequences using MEGA software.

RESULTS

In this study, a single novel homozygous mutation pLeu.1071Val in the exon 14 was found in every (100%) studied child clinically diagnosed with WD. Heterozygous mutation p.Gly1061Glu in exon14 was also found in 6 patients (11%) with WD, which is one of the common mutations in this disease. In exon 8, p.Arg778Leu mutation was detected in one patient (2.7%), which is common in the Chinese and the South Asian populations and was heterozygous. Two novel heterozygous missense mutations p.K785R (2.7%) and p.S744F (2.7%) were also found in two other children in the exon 8.

CONCLUSION

We found three novel mutations in Bangladeshi children with WD, one of which may be tagged as founder mutation for Bangladeshi population. This finding indicates the necessity to study the mutation profiles of the whole ATP7B gene in our population for risk prediction. A further large-scale study will help in the development of a Mutational Data Base of Bangladeshi population with WD.

Clinical observation and risk assessment after splenectomy in hepatolenticular degeneration patients associated with hypersplenism

Background

Both hepatolenticular degeneration (HLD) and viral hepatitis B (HBV) can cause hypersplenism, but whether splenectomy is needed or can be performed in HLD patients associated with hypersplenism is still controversial. At present, HLD combined with hypersplenism has not been listed as the indication of splenectomy.

Objective

This study aimed to investigate the efficacy, risks, and postoperative complications of splenectomy in HLD patients associated with hypersplenism.

Methods

We retrospectively analyzed the clinical data of 180 HLD patients with hypersplenism who underwent splenectomy in the Department of General Surgery, First Affiliated Hospital of Anhui University of Traditional Chinese Medicine, from January 2001 to December 2015. To evaluate the efficacy of splenectomy, the hemogram of white blood cells (WBC), red blood cells (RBC), platelets (PLT), and the liver function indexes including alanine aminotransferase, aspartate aminotransferase, and total bilirubin were recorded before surgery and 1, 3, 5, 7, and 14 days after surgery. In addition, the clinical data of 142 HBV patients with hypersplenism who underwent splenectomy over the same period were also recorded and compared with that of HLD patients. In particular, aiming to assess the risks of splenectomy in HLD, we also compared postoperative complications and 36-month mortality between the two groups.

Result

The level of WBC, RBC, and PLT were all elevated after splenectomy in both the HLD group and the HBV group. However, there was no significant difference in the variation of hemogram after splenectomy between the two groups (P > 0.05). Similarly, the variation of liver function indexes showed no statistical difference between the two groups. In terms of the incidence of postoperative complications including abdominal bleeding, pancreatic leakage, portal vein thrombosis treatment, incision infection, lung infection, and 36-month mortality, there were no significant differences between the two groups.

Conclusion

After splenectomy, the hemogram as well as liver function in the HLD group improved a lot and showed a consistent tendency with that in the HBV group. Meanwhile, compared to the HBV group, there was no significant difference in the incidence of postoperative complications in the HLD group. All these results indicate that splenectomy in HLD patients combined with hypersplenism is completely feasible and effective.

Hemorrhagic colitis induced by trientine in a 51-year-old patient with Wilson’s disease waiting for liver transplantation: A case report

BACKGROUND

Wilson’s disease (WD) is a rare inherited disorder of copper metabolism. Treatment consists of chelating agents, but side effects are common. We describe a patient who developed colitis during trientine treatment leading to decompensation of liver cirrhosis.

CASE SUMMARY

A healthy 51-year-old woman was diagnosed with liver cirrhosis due to decompensation with ascites. Etiologic evaluation raised suspicion of hereditary hemochromatosis because of compound heterozygosity HFE p.C282Y/p.H63D, and phlebotomy was started. Re-evaluation showed low ceruloplasmin, increased urinary copper excretion and the presence of Kayser-Fleischer rings. WD was confirmed by genetic analysis. Because of decompensated cirrhosis, she was referred for liver transplant evaluation. Simultaneously, treatment with trientine was initiated. Liver function initially stabilized, and the patient was not accepted for a liver transplant. Shortly after this, she developed severe hemorrhagic colitis, most probably a side effect of trientine. During that episode, she decompensated with hepatic encephalopathy. Because of a second decompensating event, she was accepted for liver transplantation, and an uneventful transplantation was carried out after clinical improvement of colitis.

CONCLUSION

Despite WD being a rare disorder, it is important to consider because it can present with a plethora of symptoms from childhood to an elderly age. Colitis should be recognized as a serious adverse drug reaction to trientine treatment that can result in decompensated liver disease.

Investigation of Thiol/Disulfide Homeostasis and Ischemia-Modified Albumin Levels in Children with Wilson Disease

BackgroundThe aim of the present study was to assess thiol/disulfide homeostasis (TDH) parameters and ischemia-modified albumin (IMA) levels in children with Wilson Disease (WD) and to compare them to healthy controls. Methods: Based on the inclusion and exclusion criteria, fifteen children with WD and twenty-nine healthy children were enrolled, and serum thiol/disulfide and IMA levels were compared between groups. Results: The mean values of native and total thiols were significantly lower in the WD group than in the control group. The mean value of disulfide was significantly higher in the WD group than in the control group. The mean percentages of disulfide/total thiol and native thiol/total thiol were higher in the WD group than in the control group. The IMA value was also higher in the WD group than in the control group. Conclusion: The present study demonstrating altered thiol/disulfide parameters indicates increased oxidative stress in children with WD.

Synonymous mutation in adenosine triphosphatase copper-transporting beta causes enhanced exon skipping in Wilson disease

Wilson disease (WD) is caused by biallelic pathogenic variants in adenosine triphosphatase copper-transporting beta (ATP7B); however, genetic testing identifies only one or no pathogenic ATP7B variant in a number of patients with WD. Synonymous single-nucleotide sequence variants have been recognized as pathogenic in individual families. The aim of the present study was to evaluate the prevalence and disease mechanism of the synonymous variant c.2292C>T (p.Phe764=) in WD. A cohort of 280 patients with WD heterozygous for a single ATP7B variant was investigated for the presence of c.2292C>T (p.Phe764=). In this cohort of otherwise genetically unexplained WD, the allele frequency of c.2292C>T (p.Phe764=) was 2.5% (14 of 560) compared to 7.1 × 10^-6 in the general population (2 of 280,964 in the Genome Aggregation Database; p < 10^-5 ; Fisher exact test). In an independent United Kingdom (UK) cohort, 2 patients with WD homozygous for p.Phe764= were identified. RNA analysis of ATP7B transcripts from patients homozygous or heterozygous for c.2292C>T and control fibroblasts showed that this variant caused high expression of an ATP7B transcript variant lacking exon 8. Conclusion: The synonymous ATP7B variant c.2292C>T (p.Phe764=) causes abnormal messenger RNA processing of ATP7B transcripts and is associated with WD in compound heterozygotes and homozygotes.

Epidemiology, clinical features, and mortality rate of Wilson disease in Moroccan children: A pediatric case series

BACKGROUND AND STUDY AIMS

Wilson's disease is an autosomal recessive disorder, that affects copper metabolism, leading to copper accumulation in the liver, nervous system, and cornea. Data are lacking on the epidemiology, the clinical and laboratory characteristics, treatment, and survival of Wilson's disease in Morocco. The aim of this study was to examine these features and the cause of death in a Moroccan pediatric population.

PATIENTS AND METHODS

The study was carried out at the University Hospital Center of Marrakesh, Morocco; 46 children were diagnosed with Wilson's disease from 2008 to 2019. The diagnosis was based on low serum ceruloplasmin, increased urinary copper concentrations, the presence of Kayser-Fleischer rings, a family history of Wilson's disease, and a Leipzig score of ≥ 4.

RESULTS

A total of 42 patients were referred to the center for hepatic or neurological manifestations; four patients were asymptomatic. Consanguineous marriage was found in 67.4% of the cases. The mean duration of illness (42 patients) was 4.9 ± 3.9 years. Kayser-Fleischer rings were found in 60.9% of 46 patients. Of the 42 symptomatic patients: 28 of 30 (93.3%) patients had low serum ceruloplasmin (<0.2 g/L), and 24 h urinary copper >100 μg/day was found in 34 of 35 (97.1%) cases. The treatment was established with D-penicillamine for 43 of the 46 patients, with zinc acetate for one patient and with zinc sulfate in for one patient, while one patient was not treated. D-penicillamine was discontinued in nine patients because of adverse effects such as thrombocytopenia, neurological deterioration, pancytopenia, severe vomiting and severe hypersensitivity. In total 28 patients were clinically and biologically stabilized, two patients experienced vision loss, and 16 patients died (38%). The main cause of death was diagnosis made at an advanced stage of disease and stopping treatment.

CONCLUSION

Wilson's disease is a rare condition associated with treatement efficacy, but late diagnosis and stopping treatment can lead to a high mortality rate.

Mutation spectrum of ATP7B gene in pediatric patients with Wilson disease in Vietnam

Background

Wilson disease (WD) is caused by mutations in the copper-transporting P-type adenosine triphosphatase encoded by the ATP7B gene. In this study, we screened and identified the ATP7B mutations among unrelated Vietnamese pediatric patients.

Methods

One-hundred-thirteen pediatric patients with clinically diagnosed WD were recruited. DNA samples were extracted from peripheral blood. Mutations in the ATP7B gene were identified by Sanger sequencing.

Results

Approximately 98% of the clinically diagnosed WD patients carried ATP7B mutations. A total of 35 different ATP7B variants were detected, including five novel mutations (L658P, L792P, T977K, IVS4 + 1G > A and IVS20 + 4A > G). Remarkably, this study revealed that S105* was the most prevalent variant (32.27%), followed by L1371P (9.09%), I1148T (7.27%), R778L (6.36%), T850I (5.45%), V176Sfs*28 and IVS14-2A > G (4.55%). Most ATP7B mutations were located in the exon 2 (37.73%), exon 16 (10.00%), exon 8 (9.55%), exon 20 (9.09%), exon 10 and exon 18 (5.45%), exon 14 (5.00%), exon 13 and intron 14 (4.55%). We developed a streamlined procedure to quickly characterize mutations in the ATP7B gene in the Vietnamese children, starting with sequencing exon 2 and subsequently to exons 8,10,13-16,18, and 20 to allow quick diagnosis of clinically suspected patients.

Conclusion

The mutational spectrum and hotspots of ATP7B gene in the Vietnamese population were fairly different from other East Asian populations. A streamlined procedure was developed to screen exon 2 in ATP7B gene among suspected WD patients to reduce genetically diagnostic cost, to facilitate early detection and intervention in countries with limited resources.

Investigation and management of Wilson's disease: a practical guide from the British Association for the Study of the Liver

Wilson's disease is an autosomal-recessive disorder of copper metabolism with hepatic, neurological, psychiatric, ophthalmological, haematological, renal, and rheumatological manifestations. Making a diagnosis can be challenging given that no single test can confirm or exclude the disease, and diagnostic delays are common. Treatment protocols vary and adverse effects, including paradoxical neurological worsening, can occur. In this Review, we provide a practical guide to the diagnosis of Wilson's disease. We include recommendations on indications for testing, how to interpret results, and when additional investigations are required. We also cover treatment initiation, ideally under the guidance of a specialist centre for Wilson's disease, and the principles behind long-term management. This guidance was developed by a multidisciplinary group of Wilson's disease experts formed through the British Association for the Study of the Liver. The guidance has been endorsed by the British Society of Gastroenterology and approved by the Association of British Neurologists.

Genetic studies discover novel coding and non-coding mutations in patients with Wilson's disease in China

OBJECTIVES

Wilson disease (WD) is a rare autosomal recessive genetic disorder associated with various mutations in the ATP7B gene and leads to significant disability or death if untreated. Early diagnosis and proper therapy usually predict a good prognosis, especially in pre-symptomatic WD. Genetic testing provides an accurate and effective diagnostic method for the early diagnosis of WD.

METHODS

We recruited 18 clinically diagnosed WD patients from 16 unrelated families and two independent individuals. The next-generation sequencing of the ATP7B gene was performed. The 293T cell lines were divided into wild-type (WT) ATP7B and mutated ATP7B groups. Cell proliferation was determined by Cell Counting Kit-8 (CCK-8) assay and apoptosis was detected by Annexin V/propidium iodide (PI) assays.

RESULTS

Pedigree analysis showed that compound heterozygous variants (17/18, 94.44%) were present in the majority of WD patients. A total of 33 ATP7B gene variants were identified, including three variants with uncertain significance (VUS) [two splice mutations (c.51+2T>G, c.1543+40G>A) and one frameshift mutation (c.3532_3535del)]. The CCK-8 and apoptosis assays demonstrated that the VUS of ATP7B could significantly affect the transportation of copper.

CONCLUSIONS

The study revealed genetic defects of 16 Chinese families and two independent individuals with WD, which enriched the mutation spectrum of the ATP7B gene worldwide and provided valuable information for studying the mutation types of ATP7B in the Chinese populations. Genetic testing in WD patients is necessary to shorten the time to initiate therapy, reduce damage to the liver and improve the prognosis.

The utility of hierarchical genetic testing in paediatric liver disease

BACKGROUND & AIMS

Genetic factors underlie a substantial proportion of paediatric liver diseases. Hereditary liver diseases have considerable genetic heterogeneity and variable clinical manifestations, which bring great challenges to clinical and molecular diagnoses. In this study, we investigated a group of paediatric patients with varying degrees of liver dysfunction using a hierarchical genetic testing strategy.

METHODS

We first applied a panel encompassing 166 known causal genes of liver disease. We then used exome sequencing (ES) in those patients whose cases remained undiagnosed to identify the genetic aetiology of their symptoms.

RESULTS

In total, we enrolled 131 unrelated paediatric patients with liver disease of Chinese Han ethnicity. We first applied targeted gene sequencing of 166 genes to all patients and yielded a diagnostic rate of 35.9% (47 of 131). Eighty-four patients who remained undiagnosed after target gene sequencing were subjected to ES. As a result, eight (8/84, 9.5%) of them obtained molecular diagnoses, including four patients suspected of abnormal bilirubin metabolism and four idiopathic cases. Non-typical genetic findings, including digenic inheritance and dual molecular diagnosis, were also identified. Through a comprehensive assessment of novel candidate variants of uncertain disease association, 11 patients of the remaining undiagnosed patients were able to obtain likely molecular diagnoses.

CONCLUSIONS

Our study presents evidence for the diagnostic utility of sequential genetic testing in a cohort of patients with paediatric liver disease. Our findings expand the understanding of the phenotypic and mutational spectrum underlying this heterogeneous group of diseases.

A Custom-Made Newborn Screening Test for Wilson’s Disease in Puerto Rico

Background

Wilson’s disease (WD) is an autosomal recessive progressive, disabling, life-threatening disease. Although early diagnosis and treatment can halt disease progression and reverse disability, diagnosis is often challenging, with a mean diagnostic delay of approximately two years. At least 98% of WD-causing variants are in the ATPase copper transporting beta (ATP7B) gene. Identifying ATP7B mutations that cause WD in Puerto Rico will allow newborn screening for WD, as well as preventive, life-saving treatment.

Methodology

TaqMan genotyping assays were performed on 174 random volunteers in southwestern Puerto Rico and on three independent WD cases for rs367956522 and rs140708492, single-nucleotide polymorphisms (SNPs) composing a WD-causing haplotype. A polymerase chain reaction followed by Sanger DNA sequencing confirmed the case genotypes. Bioinformatics analyses were performed on ATP7B polymorphisms present in The 1000 Genomes Project (1KGP) database for Puerto Rico.

Results

rs367956522 is always inherited together with rs140708492 but not vice versa. The three independent WD cases were homozygous for both SNPs, but the evidence strongly suggested that rs367956522 is the pathogenic variant. The 1KGP database revealed the presence of only one other likely pathogenic ATP7B variant, rs191312027 (Gly869Arg). Together, both variants may be responsible for causing WD in one of every 14,156 Puerto Ricans. Both are likely of European origin.

Conclusions

Genotyping probes for both variants are readily commercially available. Thus, rapid, inexpensive newborn screening for rs367956522 and rs191312027 is strongly recommended. Although these two variants may account for all or the vast majority of WD cases in Puerto Rico, other ATP7B polymorphisms described or not described in this study might also be pathogenic.

Retinoids rescue ceruloplasmin secretion and alleviate oxidative stress in Wilson's disease-specific hepatocytes

Wilson’s disease (WD) is a copper metabolic disorder caused by a defective ATP7B function. Conventional therapies cause severe side effects and significant variation in efficacy, according to cohort studies. Thus, exploring new therapeutic approaches to prevent progression to liver failure is urgent. To study the physiology and pathology of WD, immortalized cell lines and rodent WD models have been used conventionally; however, a large gap remains among different species as well as in genetic backgrounds among individuals. We generated induced pluripotent stem cells (iPSCs) from four WD patients carrying compound heterozygous mutations in the ATP7B gene. ATP7B loss- and gain-of-functions were further manifested with ATP7B-deficient iPSCs and heterozygously corrected R778L WD patient-derived iPSCs using CRISPR-Cas9-based gene editing. Although the expression of ATP7B protein varied among WD-specific hepatocytes differentiated from these iPSCs, the expression and secretion of ceruloplasmin (Cp), a downstream copper carrier in plasma, were consistently decreased in WD patient-derived and ATP7B-deficient hepatocytes. A transcriptome analysis detected abnormalities in the retinoid signaling pathway and lipid metabolism in WD-specific hepatocytes. Drug screening using WD patient-derived hepatocytes identified retinoids as promising candidates for rescuing Cp secretion. All-trans retinoic acid also alleviates reactive oxygen species production induced by lipid accumulation in WD-specific hepatocytes treated with oleic acid. These patient-derived iPSC-based hepatic models function as effective platforms for the development of potential therapeutics for hepatic steatosis in WD and other fatty liver diseases.

Neuroimaging correlates of brain injury in Wilson's disease: a multimodal, whole-brain MRI study

Wilson's disease is an autosomal-recessive disorder of copper metabolism with neurological and hepatic presentations. Chelation therapy is used to 'de-copper' patients but neurological outcomes remain unpredictable. A range of neuroimaging abnormalities have been described and may provide insights into disease mechanisms, in addition to prognostic and monitoring biomarkers. Previous quantitative MRI analyses have focused on specific sequences or regions of interest, often stratifying chronically treated patients according to persisting symptoms as opposed to initial presentation. In this cross-sectional study, we performed a combination of unbiased, whole-brain analyses on T1-weighted, fluid-attenuated inversion recovery, diffusion-weighted and susceptibility-weighted imaging data from 40 prospectively recruited patients with Wilson's disease (age range 16-68). We compared patients with neurological (n = 23) and hepatic (n = 17) presentations to determine the neuroradiological sequelae of the initial brain injury. We also subcategorized patients according to recent neurological status, classifying those with neurological presentations or deterioration in the preceding 6 months as having 'active' disease. This allowed us to compare patients with active (n = 5) and stable (n = 35) disease and identify imaging correlates for persistent neurological deficits and copper indices in chronically treated, stable patients. Using a combination of voxel-based morphometry and region-of-interest volumetric analyses, we demonstrate that grey matter volumes are lower in the basal ganglia, thalamus, brainstem, cerebellum, anterior insula and orbitofrontal cortex when comparing patients with neurological and hepatic presentations. In chronically treated, stable patients, the severity of neurological deficits correlated with grey matter volumes in similar, predominantly subcortical regions. In contrast, the severity of neurological deficits did not correlate with the volume of white matter hyperintensities, calculated using an automated lesion segmentation algorithm. Using tract-based spatial statistics, increasing neurological severity in chronically treated patients was associated with decreasing axial diffusivity in white matter tracts whereas increasing serum non-caeruloplasmin-bound ('free') copper and active disease were associated with distinct patterns of increasing mean, axial and radial diffusivity. Whole-brain quantitative susceptibility mapping identified increased iron deposition in the putamen, cingulate and medial frontal cortices of patients with neurological presentations relative to those with hepatic presentations and neurological severity was associated with iron deposition in widespread cortical regions in chronically treated patients. Our data indicate that composite measures of subcortical atrophy provide useful prognostic biomarkers, whereas abnormal mean, axial and radial diffusivity are promising monitoring biomarkers. Finally, deposition of brain iron in response to copper accumulation may directly contribute to neurodegeneration in Wilson's disease.

Comparison of the Effectiveness and Safety of d-Penicillamine and Zinc Salt Treatment for Symptomatic Wilson Disease: A Systematic Review and Meta‐Analysis

Background: Pharmacological therapy is currently the main treatment method for patients with Wilson disease (WD). We aimed to evaluate the efficacy and safety of the common treatment regimens in these patients.

Methods: We conducted a systemic review and meta-analysis by searching multiple databases for studies from inception to October 2021. Outcomes of interest were the improved rate and safety of d-penicillamine and zinc salts treatment in WD patients. Two independent reviewers performed the study selection and data extraction.

Results: Sixteen studies were included in this meta-analysis. The pooled improved rate for all included symptomatic WD patients was 78.0% (95% CI: 70.8%–85.2%). In symptomatic hepatic WD patients, there is no difference in the treatment efficiency of d-penicillamine and zinc salts (RR: 0.98, 95% CI: 0.86%–1.12%; p = 0.765). In neurological WD patients, the pooled improved rate of those who received d-penicillamine and zinc salts was 56.3% (95% CI: 37.5%–75.1%) and 80.2% (95% CI: 67.2%–93.2%), respectively. The incidence of adverse effects (RR: 2.42, 95% CI: 1.20%–4.88%; p = 0.014) and neurological deterioration (RR: 1.96, 95% CI: 1.31%–2.93%; p = 0.001) in all symptomatic WD patients treated with d-penicillamine was both higher than that of patients treated with zinc salts.

Conclusion: Our analysis suggests that symptomatic WD patients treated with d-penicillamine have higher incidence of adverse effects and neurological deterioration than that of zinc salts. The therapeutic effectiveness of these two regimens does not seem to be significantly different, and these results must be interpreted with caution.

Systematic Review Registration: PROSPERO registration, identifier CRD 42021287126.

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 Disease Prevalence: Discrepancy Between Clinical Records, Registries and Mutation Carrier Frequency

OBJECTIVES

Diagnosis of Wilson disease (WD) is difficult and, as early detection may prevent all symptoms, it is essential to know the exact prevalence to evaluate the cost-efficacy of a screening program. As the number of WD patients was high in our population, we wished to estimate prevalence by determining the carrier frequency for clinically relevant ATP7B mutations.

METHODS

To estimate prevalence, screening for the most prevalent mutation was performed in 1661 individuals with ancestry in Gran Canaria, and the frequency of other mutations was estimated from patient records. Alternatively, ATP7B mutations were detected from exomes and genomes from 851 individuals with Canarian ancestry, 236 from Gran Canaria, and a public Spanish exome database.

RESULTS

Estimated carrier frequencies in Gran Canaria ranged from 1 in 20 to 28, depending on the method used, resulting in prevalences of 1 case per 1547 to 3140 inhabitants. Alternatively, the estimated affected frequencies were 1 in 5985 to 7980 and 1 in 6278 to 16,510 in the archipelago or mainland Spain respectively.

CONCLUSIONS

The number of carriers predicts much higher prevalences than reported, suggesting that WD is underdiagnosed; specific mutations may remain unnoticed due to low penetrance or no signs of disease at all; regional prevalence rather than national prevalence should be considered in cost-efficacy models to approach preventive screening in the asymptomatic population and genetic screening strategies will have to deal with the genetic heterogeneity of ATP7B in the general population and in patients.