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.

Pediatric Wilson's Disease: Phenotypic, Genetic Characterization and Outcome of 182 Children in France.

OBJECTIVES: To describe a cohort of Wilson disease (WD) pediatric cases, and to point out the diagnostic particularities of this age group and the long-term outcome. METHODS: Clinical data of 182 pediatric patients included in the French WD national registry from 01/03/1995 to 01/06/2019 were gathered. RESULTS: Diagnosis of WD was made at a mean age of 10.7 ±â€Š4.2 years (range 1-18 years). At diagnosis, 154 patients (84.6%) had hepatic manifestations, 19 (10.4%) had neurological manifestations, and 9 patients (4.9%) were asymptomatic. The p.His1069Gln mutation was the most frequently encountered (14% of patients).Neurological patients were diagnosed at least 1 year after they presented their first symptoms. At diagnosis, the median urinary copper excretion (UCE) was 4.2 µmol/24 hours (0.2-253). The first-line treatment was d-penicillamine (DP) for 131 (72%) patients, zinc salts for 24 (13%) patients, and Trientine for 17 (9%) patients. Liver transplantation was performed in 39 (21.4%) patients, for hepatic indications in 33 of 39 patients or for neurological deterioration in 6 of 39 patients, mean Unified Wilson's Disease Rating Scale of the latter went from 90 ±â€Š23.1 before liver transplantation (LT) to 26.8 ±â€Š14.1 (P < 0.01) after a mean follow-up of 4.3 ±â€Š2.5 years. Overall survival rate at 20 years of follow-up was 98%, patient and transplant-free combined survival was 84% at 20 years. CONCLUSION: Diagnosis of WD can be challenging in children, particularly at the early stages of liver disease and in case of neurological presentation; hence the support of clinical scores and genetic testing is essential. Diagnosis at early stages and proper treatment ensure excellent outcomes, subject to good long-term treatment compliance. LT is a valid option for end-stage liver disease not responding to treatment and can be discussed for selected cases of neurological deterioration.

Liver transplantation as a rescue therapy for severe neurologic forms of Wilson disease.

OBJECTIVE: To evaluate the effect of liver transplantation (LT) in patients with Wilson disease (WD) with severe neurologic worsening resistant to active chelation. METHODS: French patients with WD who underwent LT for pure neurologic indication were retrospectively studied. Before LT and at the last follow-up, neurologic impairment was evaluated with the Unified Wilson's Disease Rating Scale (UWDRS) score, disability with the modified Rankin Scale (mRS) score, and hepatic function with the Model for End-stage Liver Disease score, together with the presence of a Kayser-Fleischer ring (KFR), brain MRI scores, and copper balance. The survival rate and disability at the last follow-up were the coprimary outcomes; evolution of KFR and brain MRI were the secondary outcomes. Prognosis factors were further assessed. RESULTS: Eighteen patients had LT. All were highly dependent before LT (median mRS score 5). Neurologic symptoms were severe (median UWDRS score 105), dominated by dystonia and parkinsonism. The cumulated survival rate was 88.8% at 1 year and 72.2% at 3 and 5 years. At the last follow-up, 14 patients were alive. Their mRS and UWDRS scores improved (p < 0.0001 and p = 0.0003). Eight patients had a major improvement (78% decrease of the UWDRS score), 4 a moderate one (41% decrease), and 2 a stable status. KFR and brain MRI scores improved (p = 0.0007). Severe sepsis (p = 0.011) and intensive care unit admission (p = 0.001) before LT were significantly associated with death. CONCLUSIONS: LT is a rescue therapeutic option that should be carefully discussed in selected patients with neurologic WD resistant to anticopper therapies (chelators or zinc salts) as it might allow patients to gain physical independency with a reasonable risk. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that for patients with WD with severe neurologic worsening resistant to active pharmacologic therapy, LT might decrease neurologic impairment.

Evaluation of the accuracy of exchangeable copper and relative exchangeable copper (REC) in a mouse model of Wilson's disease.

Wilson's disease (WD) is caused by mutations in the ATP7B gene responsible for a toxic copper overload mainly in the liver and the central nervous system. Phenotypic heterogeneity may challenge the diagnostic confirmation. Exchangeable copper (CuEXC) has recently been proposed as a new marker of WD, and its ratio to the total serum copper (Cus), Relative Exchangeable Copper (REC = CuEXC/Cus), as a diagnostic marker. This study aimed to investigate whether this could be confirmed in Atp7b-/- mice, an engineered WD animal model. Atp7b-/- (n = 137) and wild type (WT; n = 101) mice were investigated under the same conditions at 6-8, 20, 39, or 50 weeks of age. Twenty-four Atp7b-/- mice received D-penicillamine treatment from 39 to 50 weeks of age. Serum and liver [histology and intrahepatic copper (IHCu)] data were evaluated. In the WT group, all serum and liver data were normal. Atp7b-/- livers developed a chronic injury from isolated moderate inflammation (6-8 weeks: 16/33 = 48%) to inflammatory fibrosis with cirrhosis (50 weeks: 25/25 = 100% and 16/25 = 64% respectively). Cus and CuEXC increased until week 39, whereas IHCu and REC were stable with increasing age and much higher than in WT mice (mean ±â€¯SD: 669 ±â€¯269 vs. 13 ±â€¯3 µg/g dry liver and 39 ±â€¯12 vs. 11 ±â€¯3%, respectively). A threshold value of 20% for REC provided a diagnostic sensitivity and specificity of 100%, regardless of sex, age, or the use of D-penicillamine. Eleven weeks of 100 mg/kg D-penicillamine reduced liver fibrosis (p = 0.001), IHCu (p = 0.026) and CuEXC (p = 0.175). In conclusion, this study confirms REC as a WD diagnostic marker in a mouse model of chronic liver disease caused by copper overload. Further studies are needed to assess the usefulness of CuEXC to monitor the evolution of WD, particularly during treatment.

Relative exchangeable copper: A valuable tool for the diagnosis of Wilson disease.

BACKGROUND & AIMS: Measuring of the relative exchangeable copper seems to be a promising tool for the diagnosis of Wilson disease. The aim of our study is to determine the performance of REC for the diagnosis of Wilson disease in a population of patients with chronic liver diseases. METHODS: Measuring of exchangeable serum copper levels and relative exchangeable copper was performed in a group of Wilson disease patients at diagnosis or at clinical deterioration because of non-compliance (group 1, n=9), a group of stable WD patients (group 2, n=40), and two groups of patients (adult and paediatric) followed for non-Wilsonian liver diseases (group 3, n=103 and group 4, n=49 respectively). RESULTS: Exchangeable serum copper (N: 0.6-1.1 µmol/L) was significantly higher in group 1 (mean 2.2±0.7 µmol/L) compared to the other three groups: group 2=0.9±0.4 µmol/L, group 3=1.2±0.4 µmol/L, group 4=1.1±0.3 µmol/L (P<0.05). Relative exchangeable copper was significantly higher in Wilson disease patients group 1 and 2 (mean 52.6% and 43.8%) compared to patients suffering from other liver diseases (mean 7.1% and 5.9%) (P<0.05). CONCLUSIONS: Our study confirms that the determination of relative exchangeable copper is a highly valuable tool for the diagnosis of Wilson disease.

Social cognition in Wilson's disease: A new phenotype?

Studies focusing on neuropsychological impairments in Wilson's disease (WD) have highlighted that patients showing neurological signs present significant deficits in a wide range of cognitive domains. Attentional and executive impairments have also been described in people with hepatic WD. However, social cognition abilities, i.e. cognitive processes required to perceive the emotions, intentions and dispositions of other people, have not been clearly investigated in WD. In this study we examined the social cognitive functioning in 19 patients with WD depending on their clinical status-Neurological versus Non-Neurological ("hepatic") forms-compared to 20 healthy controls. For the very first time, results highlighted that patients with WD had significant impairments in the three major components of social cognition: emotion recognition, Theory of Mind and attributional style. However, these deficits differ depending on the form of the disease: patients with neurological signs showed a wide range of deficits in the three components that were assessed-results notably revealed impairments in recognizing "fear", "anger", and "disgust", a significant Theory of Mind deficit and an "aggression bias"-whereas Non-Neurological patients only showed deficits on test assessing attributional bias, with a trend to react more "aggressively" to ambiguous social situations than healthy controls, as observed in Neurological WD patients, and a specific impairment in "anger" recognition. Our findings are discussed in the light of both neurocognitive impairments and brain damages, and especially those affecting the basal ganglia, as observed in people with WD.

Liver Transplantation in Wilson's Disease with Neurological Impairment: Evaluation in 4 Patients.

BACKGROUND: The aim of this work is to report our early experiences about the benefits of liver transplantation (LT) in the treatment of persistent neurological symptoms in Wilson's disease (WD) patients. METHODS: We describe our findings in 4 WD patients with neurological impairment or symptoms treated by LT: 2 patients had transplants due to worsening of neurological symptoms despite long-term appropriate medical treatment. The other 2 required LT because of symptoms associated with liver failure. Patients were evaluated using the modified Rankin scale and the Unified Wilson's Disease Rating Scale (UWDRS). RESULTS: The 4 patients experienced neurological improvement after LT. The pre-LT Rankin score of the 2 patients transplanted due to neurological impairment was 4 compared to 3 and 2, respectively, post LT. The pre-LT Rankin scores of the 2 WD cases transplanted because of hepatic failure were 1 and 2, respectively, compared to 0 in both cases post LT. UWDRS score improved in 2 cases and remained stable in 1 less severely impaired case. Brain MRI abnormalities proved partially reversible in 3 patients and remained stable for 1 patient. CONCLUSIONS: These results suggest that LT could be envisaged for neurologically impaired WD patients.

Cognitive Abilities of Children With Neurological and Liver Forms of Wilson Disease.

Cognitive impairment in adult patients experiencing Wilson disease is now more clearly described, even in liver forms of the disease. Although this condition can appear during childhood, the cognitive abilities of children have not yet been reported in a substantial case series. This retrospective study included 21 children with Wilson disease who had undergone general cognitive assessment. The results argue in favor of a poor working memory capacity in the liver form of the disease, and more extensive cognitive impairments in its neurological form. Extensive neuropsychological investigations on all children experiencing Wilson disease are thus required.

Effect of molecular adsorbents recirculating system treatment in children with acute liver failure caused by Wilson disease.

OBJECTIVES: Because fulminant Wilson disease (WD) has an extremely poor prognosis, the use of liver support that can bridge patients to liver transplantation is lifesaving. We report the experience of albumin dialysis in acute liver failure (ALF) caused by WD in children. METHODS: Chart review of children admitted for ALF secondary to acute WD and treated by the molecular adsorbents and recirculating system. Measures of copper level in blood and within the circuit during molecular adsorbents recirculating system (MARS) sessions were performed. Clinical and biological assessments after MARS session were reported. RESULTS: Four children, with a median age of 12.3 years, were treated from 2004 to 2009 for a severe ALF associated with acute renal failure, haemolysis, and severe cholestasis. All of the children had a new Wilson index >12. A total of 14 MARS sessions were performed, for a median duration of 7.5 hours. Tolerance was good, except for 1 child who experienced haemorrhage because of vascular injury following insertion of the dialysis catheter. A neurological improvement or stabilisation was noted in all of the children along with an improvement in the Fisher index and ammonia level after MARS treatment. MARS was able to remove copper, to decrease the serum copper level of 28% in mean, and to decrease the bilirubin and creatinin levels >25%. All of the children were subsequently underwent liver transplants with a good outcome without disability. CONCLUSIONS: MARS is able to remove copper and to stabilise children with ALF secondary to WD, allowing bridging to LT.

Autoimmune hypoparathyroidism in a 12-year-old girl with McKusick cartilage hair hypoplasia.

McKusick type metaphyseal chondrodysplasia, or cartilage hair hypoplasia (CHH), is a rare autosomal recessive osteochondrodysplasia secondary to a mutation in the RMRP gene. In addition to the metaphyseal chondrodysplasia and the short-limb dwarfism, patients may present with a multisystemic disease, associating immune deficiency with recurrent infantile or childhood infections, hematological abnormalities, and gastrointestinal dysfunction. The probability of malignancy is increased in these patients, as are disimmune manifestations. We report on a 12-year-old girl with a new mutation of the RMRP gene and a severe multisystemic CHH (hematological and pulmonary lesions, severe immune deficiency, arthritis, pancreatic insufficiency, malabsorption, chronic diarrhea) receiving parenteral nutrition who presented with acute symptomatic hypocalcemia and hypercalciuria associated with the presence of autoantibodies directed against the calcium-sensor receptor. At the same time, there was an important escalation of diarrhea. Corticosteroids led to a progressive improvement of biological signs (hypocalcemia, hypoparathyroidism). By contrast, gastrointestinal symptoms and malabsorption did not improve. To our knowledge, this is the first report of autoimmune hypoparathyroidism in CHH.