ATP7B Gene Mutations in Croatian Patients with Wilson Disease

Differentially expressed lncRNAs in liver tissues of TX mice with hepatolenticular degeneration

Wilson's Disease (WD), an ATP7B-mutated inherited disease that affects copper transport, is characterised by liver and nervous system manifestations. Long non-coding (ln-c) RNAs are widely involved in almost all physiological and pathological processes in the body, and are associated with numerous diseases. The present study aimed to elucidate the lncRNA-mRNA regulation network in a TX WD mouse model using RNA sequencing (RNA-seq). lncRNA expression profiles were screened using RNA-seq and real-time polymerase chain reaction, and differentially expressed lncRNAs and mRNAs were identified. To analyse the biological functions and pathways for the differentially expressed mRNAs, gene ontology and pathway enrichment analyses were performed. A significantly correlated lncRNA-mRNA relationship pair was calculated by CNC analysis to construct differential lncRNA and mRNA co-expression networks. A total of 2564 significantly up-regulated and 1052 down-regulated lncRNAs, and 1576 up-regulated and 297 down-regulated mRNAs, were identified. These genes were found to be associated with key processes such as apoptosis, and KEGG analysis revealed enrichment in the drug metabolism-cytochrome P450 pathway, PPAR signalling pathway, Notch signalling pathway, and MAPK signalling pathway. The identified differential lncRNAs may be involved in the pathogenesis and development of WD liver injury.

Relationship between genetic mutations and clinical phenotypes in patients with Wilson disease

To study the relationship between genotype and clinical phenotype of major gene mutation sites in patients with Wilson disease (WD).Clinical and laboratory data were collected from 40 children with WD admitted to the hospital by high-pass sequencing. The basic clinical data of patients included the following: age, sex, first symptom, K-F ring, clinical classification, serum Ceruloplasmin (CP), 24 hours urine copper. High Frequency Mutations were identified in WD patients: Exon 8, Ar9778Leu, and study the relationship between high frequency mutation and clinical phenotype.The mutation frequency of 2333G>T(Arg778Leu) in Exon 8 was the highest (48%). The mutation frequency of Exon 13 at 2975C>T site was 29%. The age (t = 0.296, P = .768), sex (χ = 0.005, P = .944), first symptom (χ = 0.480, P = .449), K-F ring (χ = 0.321, P = .17), clinical classification (χ = 20.064, P > .969), serum CP levels (t = 0.007, P = .897) had no significant difference between Arg778Leu mutation group and non-Arg778Leu mutation group. Twenty-four-hour urinary copper levels (t = 12.134, P < .001,) in the Arg778Leu mutation group were higher than those in the Arg778Leu mutation group.Arg778Leu mutation is associated with 24 hours urinary copper. The study of the association between the type of gene mutation and the clinical phenotype has important implications for the occurrence regularity, pathogenesis, and disease progression in patients with WD.

Wilson disease missense mutations in ATP7B affect metal-binding domain structural dynamics

Wilson disease (WD) is caused by mutations in the gene for ATP7B, a copper transport protein that regulates copper levels in cells. A large number of missense mutations have been reported to cause WD but genotype-phenotype correlations are not yet established. Since genetic screening for WD may become reality in the future, it is important to know how individual mutations affect ATP7B function, with the ultimate goal to predict pathophysiology of the disease. To begin to assess mechanisms of dysfunction, we investigated four proposed WD-causing missense mutations in metal-binding domains 5 and 6 of ATP7B. Three of the four variants showed reduced ATP7B copper transport ability in a traditional yeast assay. To probe mutation-induced structural dynamic effects at the atomic level, molecular dynamics simulations (1.5 μs simulation time for each variant) were employed. Upon comparing individual metal-binding domains with and without mutations, we identified distinct differences in structural dynamics via root-mean square fluctuation and secondary structure content analyses. Most mutations introduced distant effects resulting in increased dynamics in the copper-binding loop. Taken together, mutation-induced long-range alterations in structural dynamics provide a rationale for reduced copper transport ability.

Presence of the p.L456V polymorphism in Cuban patients clinically diagnosed with Wilson's disease

INTRODUCTION AND AIMS

Wilson's disease is characterized by the accumulation of copper in different organs, mainly affecting the liver, brain, and cornea, and is caused by mutations in the ATP7B gene. More than 120 polymorphisms in the ATP7B gene have been reported in the medical literature. The aim of the present study was to identify the conformational changes in the exon 3 region of the ATP7B gene and detect the p.L456V polymorphism in Cuban patients clinically diagnosed with Wilson's disease.

MATERIAL AND METHODS

A descriptive study was conducted at the Centro Nacional de Genética Médica and the Instituto Nacional de Gastroenterología within the time frame of 2007-2012 and included 105 patients with a clinical diagnosis of Wilson's disease. DNA extraction was performed through the salting-out method and the fragment of interest was amplified using the polymerase chain reaction technique. The conformational shift changes in the exon 3 region and the presence of the p.L456V polymorphism were identified through the Single-Strand Conformation Polymorphism analysis.

RESULTS

The so-called b and c conformational shift changes, corresponding to the p.L456V polymorphism in the heterozygous and homozygous states, respectively, were identified. The allelic frequency of the p.L456V polymorphism in the 105 Cuban patients that had a clinical diagnosis of Wilson's disease was 41% and liver-related symptoms were the most frequent in the patients with that polymorphism.

CONCLUSION

The p.L456V polymorphism was identified in 64 Cuban patients clinically diagnosed with Wilson's disease, making future molecular study through indirect methods possible.

Three novel mutations in the ATP7B gene of unrelated Vietnamese patients with Wilson disease

Background

Wilson disease (OMIM # 277900) is a autosomal recessive disorder characterized by accumulation of copper in liver and brain. The accumulation of copper resulting in oxidative stress and eventually cell death. The disease has an onset in a childhood and result in a significant neurological impairment or require lifelong treatment. Another serious consequence of the disease is the development of liver damage and acute liver failure leading to liver transplant. The disorder is caused by mutations in the ATP7B gene, encoding a P-type copper transporting ATPase.

Case presentation

We performed genetic analysis of three unrelated patients from three different Vietnamese families. These patients had clinical features such as numbness of hands and feet, vomiting, insomnia, palsy, liver failure and Kayser–Fleischer (K–F) rings and were diagnosed with Wilson disease in the Human Genetics Department, Vietnam National Children’s Hospital. The entire coding region and adjacent splice sites of ATP7B gene were amplified and sequenced by Sanger method. Sequencing data were analyzed and compared with the ATP7B gene sequence published in Ensembl (ENSG00000123191) by using BioEdit software to detect mutations.

Conclusions

In this study, five mutations in the ATP7B gene were found. Among of these, three mutations were novel: c.750_751insG (p.His251Alafs*19) in exon 2, c.2604delC (p.Pro868Profs*5) in exon 11, and c.3077 T > A (p.Phe1026Tyr) in exon 14. Our results of the mutations associated with Wilson disease might facilitate the development of effective treatment plans.

Electronic supplementary material

The online version of this article (10.1186/s12881-018-0619-4) contains supplementary material, which is available to authorized users.

Magnetic resonance imaging findings in diagnosis and prognosis of Wilson disease

Wilson disease (WD) is a rare autosomal recessive disorder characterized by excessive copper deposition in the body, principally in the liver and the brain. There is a wide spectrum of clinical presentations, but the most significant and basic symptoms of the disease can be divided into hepatic, neurologic, and psychiatric manifestations. Magnetic resonance imaging (MRI) provides more detailed anatomical information than computed tomography of the brain, especially of the structure of the basal ganglia and brain stem. In this review, we want to evaluate the correlation between MRI findings and clinical features of WD.