ATP7B variant spectrum in a French pediatric Wilson disease cohort.

BACKGROUND/AIM: The spectrum of ATP7B variants varies significantly according to geographic distribution, and there is insufficient data on the variants observed in the French population. METHODS: Clinical data of 113 children included in the French WD national registry were gathered from March 01, 1995 to July 01, 2020. Data included epidemiological, clinical, laboratory, genetics. RESULTS: Diagnosis was made at a mean age of 11.0 ± 4.1 years (range 1-18 years). At diagnosis, 91 patients (79.8 %) had hepatic manifestations, 18 (15.8 %) presented neurological manifestations, and 4 patients (3.5 %) were asymptomatic. Only 29 patients (25 %) were homozygous for a variant. We have found a total of 102 different variants including 14 novel variants. Recurrent variant p.His1069Gln was the most prevalent, n = 31 alleles (14,2%), with only seven homozygous; in contrast 55% of variants are identified in only one family. 45% were truncating variants. In respect of mutated exon, the three most prevalent were exon 14 (16.5%), exon 8 (13.8%), and exon 3 (11.5%). When considering patients with two Nonsense / Frameshift variants as a group and those with two Missense variants, we found significantly lower ceruloplasmin for the former: 2.8 ± 0.7 mg/dl vs 8.4 ± 5mg/dl (p<0.05). CONCLUSION: p.His1069Gln is the most frequent variant (14,2%) and exons 14, 8, and 2 of the ATP7B gene account for 41.7% of total variants. However, there is significant heterogeneity in the French population concerning the other ATP7B variants. Nonsense / Frameshift variants were associated with lower ceruloplasmin levels.

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.

Reproductive function of long-term treated patients with hepatic onset of Wilson's disease: a prospective study.

RESEARCH QUESTION: Wilson's disease (WD) is a disorder of copper metabolism that can cause hormonal alterations. The impact of WD and its therapies on fertility is not well defined. The aim of this study was to evaluate ovarian reserve and sperm parameters in long-term treated WD patients with hepatic onset. DESIGN: WD patients with hepatic onset treated for at least 5 years were compared with healthy controls. Men underwent spermiogram and sperm DNA fragmentation (SDF) analysis. Women were tested for serum FSH, anti-Müllerian hormone (AMH) and sonographic antral follicle count (AFC) in the early follicular phase. Ovulation was monitored with ultrasound and progesterone serum concentrations in the luteal phase. RESULTS: The WD group included 26 patients (12 males), the control group 19 subjects (9 males). All patients apart from four (one male) were responders to WD treatment. Sperm count and morphology were comparable between cases and controls. Sperm motility (total and after 1 h) was significantly lower in cases (44.78 ± 21.65%; 47.85 ± 21.52%) than controls (61.88 ± 11.03; 69.44 ± 11.02%, P = 0.03 and 0.01, respectively). The only non-responder had severe oligo-astheno-teratozoospermia. SDF values were normal in cases and controls. AMH, AFC and FSH did not differ between cases and controls. LH was significantly lower in cases (3.36 ± 1.65 mIU/ml) than controls (6.25 ± 1.03 mIU/ml, P < 0.0001). A non-responder woman who developed neurological signs had a 7-year history of infertility. CONCLUSIONS: WD patients with hepatic onset, diagnosed early and treated, have no impairment in fertility potential even if males show reduced sperm motility and females lower LH values. Only patients with poor disease control have some evidence of impaired fertility.

Total and Exchangeable Copper Assay Using Inductively Coupled Plasma Mass Spectrometry and Establishment of a Pediatric Reference Interval.

CONTEXT.­: Recently, an exchangeable copper (CuEXC) assay has been suggested as a robust and feasible diagnostic tool for Wilson disease (WD). Although WD is a disorder that requires lifelong treatment and monitoring, few data are currently available regarding the status of copper levels in children. OBJECTIVE.­: To evaluate the performance of copper assays and establish a reference interval for total copper and CuEXC in the pediatric population. DESIGN.­: Serum samples from children aged 1-5 (n = 122), 6-12 (n = 125), and 13-18 years (n = 120) were analyzed. Total copper and CuEXC concentrations were directly measured using inductively coupled plasma mass spectrometry, and relative CuEXC levels were calculated. Total copper reference intervals, CuEXC levels, and relative CuEXC levels were determined based on the 2.5th and 97.5th percentiles of the data with 90% confidence intervals. RESULTS.­: There were significant differences in the median concentrations of total copper and relative CuEXC among the age groups. Reference intervals determined for total copper were 82 to 167, 75 to 139, and 64 to 133 µg/dL for children aged 1 to 5, 6 to 12, and 13 to 18 years, respectively. The reference intervals for CuEXC were 4.29 to 9.79, 4.02 to 9.09, and 3.55 to 8.25 µg/dL for children aged 1 to 5, 6 to 12, and 13 to 18 years, respectively. Among 11 patients with suspected WD, relative CuEXC values were elevated in all 3 diagnosed with WD. CONCLUSIONS.­: The pediatric reference intervals derived in this study are expected to be useful for the diagnosis, differential diagnosis, treatment, and monitoring of pediatric patients with WD.

Wilson disease: revision of diagnostic criteria in a clinical series with great genetic homogeneity.

BACKGROUND: Wilson disease is an autosomal recessive disorder of copper metabolism caused by mutations in the ATP7B gene. An early diagnosis is crucial to prevent evolution of the disease, as implantation of early therapeutic measures fully prevents its symptoms. As population genetics data predict a higher than initially expected prevalence, it was important to define the basic diagnostic tools to approach population screening. METHODS: A highly genetically homogeneous cohort of 70 patients, belonging to 50 unrelated families, has been selected as a framework to analyze all their clinical, biochemical and genetic characteristics, to define the disease in our population, with an estimated prevalence of 1 in 12,369, and determine the most useful features that reach diagnostic value. RESULTS: Serum ceruloplasmin below 11.5 mg/dL and cupremia below 60 µg/mL, were the best analytical predictors of the disease in asymptomatic individuals, while cupruria or hepatic copper determination were less powerful. Genetic analysis reached a conclusive diagnosis in all 65 patients available for complete testing. Of them, 48 were carriers of at least one p.Leu708Pro mutant allele, with 24 homozygotes. Nine patients carried a promoter deletion mutation, revealing that extended sequencing beyond the ATP7B gene-coding region is essential. All mutations caused hepatic damage since early ages, increasing its severity as diagnosis was delayed, and neurological symptoms appear. CONCLUSION: Serum ceruloplasmin determination followed by genetic screening would reduce costs and favor the prioritization of non-invasive procedures to reach a definitive diagnosis, even for asymptomatic cases.

The blood copper isotopic composition is a prognostic indicator of the hepatic injury in Wilson disease.

Wilson disease (WD) is an autosomal recessive disorder of copper (Cu) metabolism. The gene responsible for WD, ATP7B, is involved in the cellular transport of Cu, and mutations in the ATP7B gene induce accumulation of Cu in the liver and ultimately in the brain. In a pilot study, the natural variations of copper stable isotope ratios (65Cu/63Cu) in the serum of WD patients have been shown to differ from that of healthy controls. In the present study, we challenged these first results by measuring the 65Cu/63Cu ratios in the blood of treated (n = 25), naïve patients (n = 11) and age matched healthy controls (n = 75). The results show that naïve patients and healthy controls exhibit undistinguishable 65Cu/63Cu ratios, implying that the Cu isotopic ratio cannot serve as a reliable diagnostic biomarker. The type of treatment (d-penicillamine vs. triethylenetetramine) does not affect the 65Cu/63Cu ratios in WD patients, which remain constant regardless of the type and duration of the treatment. In addition, the 65Cu/63Cu ratios do not vary in naïve patients after the onset of the treatment. However, the 65Cu/63Cu ratios decrease with the degree of liver fibrosis and the gradient of the phenotypic presentation, i.e. presymptomatic, hepatic and neurologic. To get insights into the mechanisms at work, we study the effects of the progress of the WD on the organism by measuring the Cu concentrations and the 65Cu/63Cu ratios in the liver, feces and plasma of 12 and 45 week old Atp7b-/- mice. The evolution of the 65Cu/63Cu ratios is marked by a decrease in all tissues. The results show that 63Cu accumulates in the liver preferentially to 65Cu due to the preferential cellular entry of 63Cu and the impairment of the 63Cu exit by ceruloplasmin. The hepatic accumulation of monovalent 63Cu+ is likely to fuel the production of free radicals, which is potentially an explanation of the pathogenicity of WD. Altogether, the results suggest that the blood 65Cu/63Cu ratio recapitulates WD progression and is a potential prognostic biomarker of WD.

Assay in serum of exchangeable copper and total copper using inductively coupled plasma mass spectrometry (ICP-MS): development, optimisation and evaluation of a routine procedure.

The assay in serum of non-caeruloplasmin copper, as exchangeable copper after complexation with EDTA (ExCu) and total copper has been evaluated and compared in patients with varying c-reactive protein(CRP). Measurement of ExCu and total copper, range 0.2-47.2 µmol/L, was developed using ICP-MS. The chelating agents EDTA and TEPA were compared over 0.0-10 g/L after incubation with serum for 60 mins followed by ultrafiltration with Amicon 10 kDa filter. The assay for ExCu was optimised with EDTA 3 g/L (8.1 mmol/L) maintained at pH 7.0-8.0 before ultrafiltration. TEPA was not as selective in chelation of copper. Patients n = 82 were studied in relation to changes in inflammatory marker CRP and a group of patients n = 37 with normal CRP. The ExCu assay gave excellent recoveries (94-102 % but poor recovery for free uncomplexed copper), good repeatability, limit of quantitation 0.19 µmol/l with a provisional reference range 0.48 to 1.63 µmol/L (n = 37 patients). The range for relative exchangeable copper (exchangeable copper divided by total serum copper) was 2.49 to 9.96 %. ExCu was elevated in conditions with increased CRP greater than 100 mg/L suggesting an effect of inflammation on the free copper fraction. A reliable and reproducible assay for ExCu and total copper has been developed. The upregulated inflammatory state increases the ExCu suggesting excess free copper.

LC-ICP-MS method for the determination of "extractable copper" in serum.

Copper is an essential element for biological functions within humans and animals. There are several known diseases associated with Cu deficiency or overload, such as Menkes disease and Wilson disease, respectively. A common clinical method for determining extractable Cu levels in serum, which is thought to be potentially dangerous if in excess, is to subtract the value of tightly incorporated Cu in ceruloplasmin from total serum Cu. In this work, an automated sample preparation and liquid chromatography (LC) system was combined with inductively coupled plasma-mass spectrometry (ICP-MS) to determine bound Cu and extractable Cu in serum. This LC-ICP-MS method took 250 s for sample preparation and analysis, followed by a column recondition/system reset, thus, a 6 minute sample-to-sample time including sample preparation. The method was validated using serum collected from either control (Atp7b+/-) or Wilson disease rats (Atp7b-/-). The extractable Cu was found to be 4.0 ± 2.3 µM Cu in healthy control rats, but 2.1 ± 0.6 µM Cu in healthy Wilson rats, and 27 ± 16 µM Cu in diseased Wilson rats, respectively. In addition, the extractable Cu/bound Cu ratio was found to be 6.4 ± 3.5%, 38 ± 29%, and 34 ± 22%, respectively. These results suggest that the developed method could be of diagnostic value for Wilson disease, and possibly other copper related diseases.

A study of susceptibility-weighted imaging in patients with Wilson disease during the treatment of metal chelator.

OBJECTIVE: A randomized-controlled trial comparing study of the changes in brain sensitive-weighted imaging (SWI) of Wilson disease (WD) patients during the treatment with metal chelator was done. METHODS: 100 untreated WD patients (80 cases of cerebral type, 20 cases of hepatic type, age 20.13 ± 9.12 years old) and 20 normal controls were selected. Neurological symptoms were scored using the modified Young scale. Liver function tests and copper indices were collected. All study objects received SWI test of the brain. The values of corrected phase (CP) were calculated on SWI. Cerebral-type WD patients were treated with D-penicillamine (DPA) (group 1) or Dimercaptopropane Sulfonate (DMPS) + Dimercaptosuccinic Acid (DMSA) (group 2). Hepatic-type WD patients were treated with DPA (group 3). All patients received annual neurological symptom score, liver function, copper indices, and SWI examination. RESULTS: At the first year of treatment, score of the modified Young scale in group 2 was lower than that in group 1 (P = 0.023) and lower than that before treatment (P = 0.040). After 2 years of treatment, the score of the modified Young scale in group 1 was lower than that before treatment (P = 0.012). At the second year after treatment, the urinary copper in group 2 was higher than that in group 1 (P = 0.014). Urinary copper was maintained at 200 µg/day in group 1 and 300 µg/day in group 2 after 3 years of treatment. At the first year of treatment, serum copper in group 1 was lower than that in group 2 (P = 0.032). At the first year of treatment, CP values of the pallidum and substantia nigra in group 2 were higher than those in group 1 (P = 0.026, 0.040). At the second year of treatment, CP value of substantia nigra in group 2 was higher than that in group 1 (P = 0.037). After 3 years of treatment, there was no difference in CP values between WD patients and normal controls. CONCLUSIONS: Therapy with DMPS and DMSA improves neurological symptoms of WD patients more quickly and leads to less aggravation, compared with therapy with DPA. The metal content in the brain of WD patients was at a low level after 3 years of treatment. DMPS and DMSA can remove metal from brain tissue faster than DPA.

The co-occurrence of Wilson disease and X-linked agammaglobulinemia in one family highlights the promising diagnostic potential of proteolytic analysis.

BACKGROUND: We report the first case of a family with co-occurrence of Wilson disease (WD), an autosomal recessive disorder of copper metabolism, and X-linked agammaglobulinemia (XLA), a primary immunodeficiency disorder (PIDD) that features marked reduction in circulating B lymphocytes and serum immunoglobulins. METHODS AND RESULTS: Through utilization of a multiplexed biomarker peptide quantification method known as the immuno-SRM assay, we were able to simultaneously and independently identify which family members are affected with WD and which are affected with XLA using dried blood spots (DBS). CONCLUSION: Being able to delineate multiple diagnoses using proteolytic analysis from a single DBS provides support for implementation of this methodology for clinical diagnostic use as well as large-scale population screening, such as newborn screening (NBS). This could allow for early identification and treatment of affected individuals with WD or XLA, which have been shown to reduce morbidity and decrease mortality in these two populations.

Biomedical copper speciation in relation to Wilson's disease using strong anion exchange chromatography coupled to triple quadrupole inductively coupled plasma mass spectrometry.

Biomedical analytical methods often rely on indirect measurements, such as immunoassays, which can lack effective metrological traceability. In the nephelometric determination of ceruloplasmin (Cp), an important protein whose circulating level is altered in Wilson's disease (WD), the anti-Cp antibody used is not specific for the biologically active holoprotein so the assay can overestimate the concentration of Cp due to the presence of the apoprotein. By providing quantitation using elemental standards, the use of strong anion exchange chromatography (SAX) coupled to triple quadrupole inductively coupled plasma mass spectrometry (ICP-MS-MS) can overcome the drawbacks of methods for the measurement of metalloproteins reliant on immunoassays. In the current study, a SAX-ICP-MS-MS method for Cp quantification was designed and tested in samples of blood serum of WD patients and healthy controls. Using standards based on a copper-EDTA complex for calibration, the method provides relatively simple quantification of Cp with the limit of detection of 0.1 µg L-1 (limit of quantification 0.4 µg L-1). The method was also used to investigate the copper species separated by using a 30 kDa cut-off ultrafiltration device. The so-called "exchangeable" copper fraction is considered as an alternative clinical biomarker of WD. Using the designed speciation approach, it was shown that the ultrafiltration method can overestimate the "exchangeable" copper fraction due to a removal of copper from Cp. This was confirmed by comparing the enzymatic activity of the fractions. Thus, the specificity of the "exchangeable" copper test can be ensured only under strict maintenance of ultrafiltration conditions.

Is it possible to diagnose fulminant Wilson's disease with simple laboratory tests?

BACKGROUND: Wilson's disease is a rare cause of acute liver failure and is highly fatal without liver transplantation. Fast and accurate diagnostic methods are needed for fulminant Wilson's disease (FWD). In this study, we aimed to develop an early, simple and accurate diagnostic method to differentiate FWD from nonwilsonian acute liver failure (NWALF) causes using routine biochemical data. METHODS: The medical records of 24 paediatric FWD and 120 paediatric NWALF cases diagnosed at the Department of Pediatric Gastroenterology, Hepatology, and Nutrition between January 2007 and February 2017 were retrospectively reviewed. RESULTS: Using receiver operator characteristics curve (ROC) analysis, we have determined the best cut-off point for laboratory findings in FWD. Patients meeting these cut-off points were assigned one point and others were assigned zero point. We then formed a new variable consisting of the combination of 14 variables and performed a new ROC analysis. We obtained a cut-off point of ≥4.5 for FWD. The diagnostic performance of the score was characterized by a sensitivity of 0.889, a specificity of 0.879 (P < .001). A scoring system based only on aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase, AST/ALT ratio, uric acid and haemoglobin had a best cut-off point of ≥2.5 for FWD, which had a sensitivity of 0.875, a specificity of 0.867 (P < .001). CONCLUSIONS: Our study demonstrated that biochemical markers offer almost as reliable, fast and accurate diagnosis of FWD as offered by ceruloplasmin and 24-hour urinary copper.

Comprehensive and comparative exploration of the Atp7b-/- mouse plasma proteome.

Wilson's disease (WD), a rare genetic disease caused by mutations in the ATP7B gene, is associated with altered expression and/or function of the copper-transporting ATP7B protein, leading to massive toxic accumulation of copper in the liver and brain. The Atp7b-/- mouse, a genetic and phenotypic model of WD, was developed to provide new insights into the pathogenic mechanisms of WD. Many plasma proteins are secreted by the liver, and impairment of liver function can trigger changes to the plasma proteome. High standard proteomics workflows can identify such changes. Here, we explored the plasma proteome of the Atp7b-/- mouse using a mass spectrometry (MS)-based proteomics workflow combining unbiased discovery analysis followed by targeted quantification. Among the 367 unique plasma proteins identified, 7 proteins were confirmed as differentially abundant between Atp7b-/- mice and wild-type littermates, and were directly linked to WD pathophysiology (regeneration of liver parenchyma, plasma iron depletion, etc.). We then adapted our targeted proteomics assay to quantify human orthologues of these proteins in plasma from copper-chelator-treated WD patients. The plasma proteome changes observed in the Atp7b-/- mouse were not confirmed in these samples, except for alpha-1 antichymotrypsin, levels of which were decreased in WD patients compared to healthy individuals. Plasma ceruloplasmin was investigated in both the Atp7b-/- mouse model and human patients; it was significantly decreased in the human form of WD only. In conclusion, MS-based proteomics is a method of choice to identify proteome changes in murine models of disrupted metal homeostasis, and allows their validation in human cohorts.

Adjunctive Antioxidant Therapy in Neurologic Wilson's Disease Improves the Outcomes.

Oxidative stress has been reported in Wilson's disease with neurological manifestation (WDNM), but there is a paucity of studies on the role of adjunctive antioxidant therapy. This study aims to evaluate the efficacy of adjunctive vitamin C and E treatment in reducing oxidative stress and improving clinical outcomes. Forty-nine patients with WDNM were included and their clinical details were noted. Glutathione (GSH), total antioxidant capacity (TAC), and malondialdehyde (MDA) were measured using spectrophotometer at baseline and follow-up. All patients received zinc with or without chelating therapy, and 32 of them prescribed vitamin C (500 mg/day) and E (400 mg/day). Clinical outcomes at 6, 12, and 24 months were categorized as improved, static, or worsened based on improvement in Burke-Fahn-Marsden (BFM) score (>10%) and/or severity grade (> 1). Baseline parameters were similar between two groups; except BFM score was higher in the antioxidant group. At follow-up, the antioxidant group had higher GSH, TAC, and lower MDA levels compared with baseline. Patients on antioxidant treatment experienced improvement more frequently at 6 (53.1% vs. 29.4%), 12 (62.5% vs. 29.4%), and 24 months (68.8% vs. 35.3%) compared with those without antioxidant treatment. In WDNM, adjunctive vitamin C and E treatment reduce oxidative stress and improve clinical outcome.

Characterization of Fibrinogen as a Key Modulator in Patients with Wilson's Diseases with Functional Proteomic Tools.

Wilson's disease (WD) is an autosomal recessive disorder of copper metabolism caused by defects in the ATPase gene (ATP7B). The various clinical features result from the massive accumulation of copper in the liver, cornea and basal ganglia. Although WD can be effectively treated with proper medicine, this disease is difficult to clearly diagnose due to its indefinite symptoms. In the current study, we achieved a positive correlation between clinical symptoms and the enzymatic activity of ceruloplasmin in WD patients. Furthermore, proteome profiles of plasma as well as network analysis demonstrated that fibrinogen is a critical indicator which is significantly unregulated in WD subjects in comparison to healthy donors and closely linked to pathogenesis of WD. Here, we applied 2DE-immunoblots and immunohistochemistry to verify the protein level and localization in situ. The enhanced expression of fibrinogen in the plasma of WD subjects with respect to that of healthy controls and patients with distinct disorders was also confirmed by utilizing clinical samples. As expected, application of high dose of copper induced expression of fibrinogen, while knockdown of ceruloplasmin also resulted in upregulation of fibrinogen as well as elimination of superoxide dismutase (SOD), leading to increased oxidative stress in cells. In summary, the liver injury or oxidative stress induced by the progression of WD may account for the obvious increase of fibrinogen, which in turn triggers inflammatory responses and interferes coagulation cascades; this finding sheds light on the early detection and diagnosis of WD.

The effects of iron and zinc status on prognosis in pediatric Wilson's disease.

OBJECTIVES: Wilson's disease (WD) is a metabolic disorder leading to hepatic and extrahepatic copper deposition. Several studies have reported that besides copper (Cu), iron (Fe) and zinc (Zn) are also accumulated at varying levels in various tissues in WD. However, there is not an adequate number of studies investigating the effects of Fe and Zn status on WD presentation and prognosis. We aimed to evaluate serum levels of ferritin (SFr), copper (SCu), and zinc (SZn) in WD and determine their role in disease presentation and prognosis. MATERIALS-METHOD: We retrospectively reviewed the medical records of 97 pediatric patients with WD who were diagnosed and followed at Inönü University Pediatric Gastroenterology, Hepatology and Nutrition Department between January 2006 and May 2017. Serum Cu and Zn levels were analyzed by using flame atomic absorption spectrophotometer. Ferritin was analyzed by chemiluminescence immunoassay method. RESULTS: Analysis of serum levels of the elements according to the type of presentation, there was no significant difference between the groups for ceruloplasmin. However, SCU, FSCu, SFr and 24 h urinary copper levels were significantly higher (p = 0.002, p = 0.003, p = 0.023 and p < 0.001, respectively) and SZn and CSZn levels were significantly lower (fulminant WD). p < 0.001, p < 0.001). There was a positive correlation between SFr, SCu serum levels and mortality scores (respectively, r: 0.501, 0.564 for PELD, r:0.490, 0.504 for MELD, r: 0.345, 0.374 for Dhwan), and a negative correlation between SZn level and mortality scores. (r:-0.650 for PELD, r:-0.703 for MELD, r:-0.642 for Dhwan) We used the ROC curves to determine the worst prognosis for fulminant Wilson disease. According to these limit values, we found that the sensitivity and specificity of FWD development was significantly higher. (for SZn sensitivity of 91.5%, a specificity of 100%, p=<0,001, for SCu predicted FWD development with a sensitivity of 100%, a specificity of 73.7%, p=<0,001, for SFr predicted FWD development with a sensitivity of 92.9%, a specificity of 66.2%, p < 0,001) CONCLUSION: Our study suggests that SFr, SCu, SZn levels might have prognostic importance for WD.

Single nucleotide polymorphisms in the human ATP7B gene modify the properties of the ATP7B protein.

Single nucleotide polymorphisms (SNPs) are the largest source of sequence variation in the human genome. However, their functional significance is not well understood. We show that SNPs in the Wilson disease gene, ATP7B, that produce amino-acid substitutions K832R and R952K, modulate ATP7B properties in vitro and influence serum copper (Cu) status in vivo. The presence of R832 is associated with a lower ATP7B abundance and a diminished trafficking in response to elevated Cu. The K832R substitution alters surface exposure of amino acid residues in the actuator domain and increases its conformational flexibility. All SNP-related ATP7B variants (R832/R952, R832/K952, K832/K952, and K832/R952) have Cu-transport activity. However, the activity of ATP7B-K832/K952 is lower compared to other variants. In humans, the presence of K952 is associated with a higher fraction of exchangeable Cu in serum. Thus, SNPs may modulate the properties of ATP7B and the organism Cu status.

Metabolomics profiles of patients with Wilson disease reveal a distinct metabolic signature.

INTRODUCTION: Wilson disease (WD) is characterized by excessive intracellular copper accumulation in liver and brain due to defective copper biliary excretion. With highly varied phenotypes and a lack of biomarkers for the different clinical manifestations, diagnosis and treatment can be difficult. OBJECTIVE: The aim of the present study was to analyze serum metabolomics profiles of patients with Wilson disease compared to healthy subjects, with the goal of identifying differentially abundant metabolites as potential biomarkers for this condition. METHODS: Hydrophilic interaction liquid chromatography-quadrupole time of flight mass spectrometry was used to evaluate the untargeted serum metabolome of 61 patients with WD (26 hepatic and 25 neurologic subtypes, 10 preclinical) compared to 15 healthy subjects. We conducted analysis of covariance with potential confounders (body mass index, age, sex) as covariates and partial least-squares analysis. RESULTS: After adjusting for clinical covariates and multiple testing, we identified 99 significantly different metabolites (FDR < 0.05) between WD and healthy subjects. Subtype comparisons also revealed significantly different metabolites compared to healthy subjects: WD hepatic subtype (67), WD neurologic subtype (57), WD hepatic-neurologic combined (77), and preclinical (36). Pathway analysis revealed these metabolites are involved in amino acid metabolism, the tricarboxylic acid cycle, choline metabolism, and oxidative stress. CONCLUSIONS: Patients with WD are characterized by a distinct metabolomics profile providing new insights into WD pathogenesis and identifying new potential diagnostic biomarkers.