Population screening and diagnostic strategies in screening family members of Wilson's disease patients

[Wilson's disease: overview]

Wilson's disease (WD) is an uncommon hereditary disorder caused by a deficiency in the ATP7B transporter. The protein codified by this gene facilitates the incorporation of the copper into ceruloplasmin. Therefore, WD accumulates copper primary in the liver and secondary in other organs, such as the central nervous system. It represents a wide spectrum of disease, ranging from being asymptomatic in some patients to promote an acute liver failure in others. The diagnosis requires a combination of clinical signs and symptoms, as well as some diagnostic tests such as the measurement of serum ceruloplasmin, the urinary excretion of copper, the liver biopsy or the genetic testing. The treatment must be maintained lifelong and includes some drugs such as chelating agents (penicillamine and trientine) and inhibitors of the copper absorption (zinc salts). Lastly, the liver transplant should be an option for patients with end-stage liver disease.

Liver transplantation as a treatment for Wilson's disease with neurological presentation: a systematic literature review

Introduction

Wilson’s disease (WD) is a potentially treatable, genetic disorder of copper metabolism, with survival similar to healthy populations if controlled. However, in almost 50% of WD patients, neurological symptoms persist despite treatment, and in up to 10% of patients, neurological deterioration is irreversible. International guidelines on WD treatment do not recommend liver transplantation (LT) as a treatment for neurological symptoms in WD. However, such treatment has been assessed in retrospective analyses, case and series reports. We aimed to systematically assess all available evidence on the effectiveness and safety of LT in WD patients with neurological presentation.

Methods

This systematic literature review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies were identified by searching the PubMed database (up to 6 April 2021) and by screening reference lists.

Results

Based on the systematic literature review, 48 articles were identified, showing outcomes of LT in 302 WD patients with neurological symptoms. Of these patients, major improvement was found in 215 cases (71.2%), with no difference in neurological status before and after LT in 21 cases (6.9%). There were 29 deaths (9.6%), neurological worsening in 24 cases (7.9%), and 13 cases (4.3%) were lost to follow-up.

Conclusions

The results suggest that LT is a promising method of WD management in patients with severe, neurological symptoms, particularly if the patient has not responded to pharmacological de-coppering treatment. Further studies of LT in these patients are warranted.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13760-022-01872-w.

Inborn Errors of Metabolism Screening in Neonates: Current Perspective with Diagnosis and Therapy

Inborn errors of metabolism (IEMs) are rare hereditary or acquired disorders resulting from an enzymatic deformity in biochemical and metabolic pathways influencing proteins, fats, carbohydrate metabolism, or hampered some organelle function. Even though individual IEMs are uncommon, together, they represent a diverse class of genetic diseases, with new issues and disease mechanisms being portrayed consistently. IEM includes the extraordinary multifaceted nature of the fundamental pathophysiology, biochemical diagnosis, molecular level investigation, and complex therapeutic choices. However, due to the molecular, biochemical, and clinical heterogeneity of IEM, screening alone will not detect and diagnose all illnesses included in newborn screening programs. Early diagnosis prevents the emergence of severe clinical symptoms in the majority of IEM cases, lowering morbidity and death. The appearance of IEM disease can vary from neonates to adult people, with the more serious conditions showing up in juvenile stages along with significant morbidity as well as mortality. Advances in understanding the physiological, biochemical, and molecular etiologies of numerous IEMs by means of modalities, for instance, the latest molecular-genetic technologies, genome engineering knowledge, entire exome sequencing, and metabolomics, have prompted remarkable advancement in detection and treatment in modern times. In this review, we analyze the biochemical basis of IEMs, clinical manifestations, the present status of screening, ongoing advances, and efficiency of diagnosis in treatment for IEMs, along with prospects for further exploration as well as innovation.

Quality of Life in Wilson's Disease: A Systematic Literature Review

Background: Wilson's disease (WD) is a rare inherited genetic disorder characterized by the progressive accumulation of copper in the brain, liver, and other major organ systems. To date, there have been no comprehensive studies synthesizing evidence pertaining to the quality of life (QOL) in WD. Objective: We conducted a systematic literature review to identify and synthesize the evidence on QOL in patients with WD. Methods: To address this gap in the literature, we conducted a systematic literature review in MEDLINE and EMBASE to identify observational studies and clinical trials reporting QOL outcomes among people living with WD. Results: A total of 442 publications were identified, 41 publications were eligible for full-text screening, and 7 articles, representing 7 studies, met all inclusion criteria. QOL questionnaires used across studies included the 12-Item Short Form Health Survey Questionnaire (version 1) (SF-12) (n=2), the 36-Item Short Form Health Survey Questionnaire (version 1) (SF-36) (n=3), Global Assessment Scale (GAS) (n=1), and World Health Organization QOL brief questionnaire (WHO-QOL-BREF) (n=1). Overall, the pattern in QOL from most studies demonstrated a worse QOL in WD patients compared with the general population, a deterioration in QOL for patients presenting with neurologic symptoms, and more frequent psychiatric symptoms compared with the ones with hepatic symptoms. Discussion: Although our understanding of the underlying pathophysiology of WD has advanced, and novel therapeutics are on the horizon, our understanding of how WD affects overall QOL remains limited. Evidence from this review demonstrates the substantial heterogeneity in reporting outcomes pertaining to the QOL associated with WD. These differences may be attributable to the fact that QOL is not typically assessed and the lack of a standardized method for assessing QOL in WD. Conclusion: This review demonstrates a need for more up-to-date studies with larger sample sizes to further evaluate QOL in patients with WD. The study also demonstrates the need for a WD-specific instrument to measure the QOL in WD patients.

Wilson's disease: Revisiting an old friend

Wilson's disease (WD) is a rare condition caused by copper accumulation primarily in the liver and secondly in other organs, such as the central nervous system. It is a hereditary autosomal recessive disease caused by a deficiency in the ATP7B transporter. This protein facilitates the incorporation of copper into ceruloplasmin. More than 800 mutations associated with WD have been described. The onset of the disease frequently includes manifestations related to the liver (as chronic liver disease or acute liver failure) and neurological symptoms, although it can sometimes be asymptomatic. Despite it being more frequent in young people, WD has been described in all life stages. Due to its fatal prognosis, WD should be suspected in all patients with unexplained biochemical liver abnormalities or neurological or psychiatric symptoms. The diagnosis is established with a combination of clinical signs and tests, including the measurement of ceruloplasmin, urinary copper excretion, copper quantification in liver biopsy, or genetic assessment. The pharmacological therapies include chelating drugs, such as D-penicillamine or trientine, and zinc salts, which are able to change the natural history of the disease, increasing the survival of these patients. In some cases of end-stage liver disease or acute liver failure, liver transplantation must be an option to increase survival. In this narrative review, we offer an overview of WD, focusing on the importance of clinical suspicion, the correct diagnosis, and treatment.

A Comprehensive Analysis and Splicing Characterization of Naturally Occurring Synonymous Variants in the ATP7B Gene

Next-generation sequencing is effective for the molecular diagnosis of genetic diseases. However, the identification of the clinical significance of synonymous variants remains a challenge. Our previous study showed that some synonymous variants in ATP7B gene produced splicing disruptions, leading to Wilson disease (WD). To test the hypothesis that synonymous variants of ATP7B cause abnormal splicing by disrupting authentic splice sites or splicing regulatory elements, we used computational tools and minigene assays to characterize 253 naturally occurring ATP7B gene synonymous variants in this study. Human Splicing Finder (HSF) and ESE Finder 3.0 were used to predict the impact of these rare synonymous variants on pre-mRNA splicing. Then, we cloned 14 different wild-type Minigene_ATP7B_ex constructs for in vitro minigene assay, including 16 exons of ATP7B gene. After computational prediction, 85 candidate variants were selected to be introduced into the corresponding Minigene_ATP7B_ex constructs for splicing assays. Using this two-step procedure, we demonstrated that 11 synonymous variants in ExAc database (c.1620C>T, c.3888C>T, c.1554C>T, c.1677C>T, c.1830G>A, c.1875T>A, c.2826C>A, c.4098G>A, c.2994C>T, c.3243G>A, and c.3747G>A) disrupted RNA splicing in vitro, and two (c.1620C>T and c.3243G>A) of these caused a complete exon skipping. The results not only provided a reliable experimental basis for the genetic diagnosis of WD patients but also offered some new insights into the pathogenicity of synonymous variants in genetic diseases.