Wilson Disease Mohit Bhatt Director Neurosciences Wilson Disease - PowerPoint PPT Presentation

Wilson Disease Mohit Bhatt Director Neurosciences Wilson Disease Clinic Kokilaben Dhirubhai Ambani Hospital & Medical Research Institute Mumbai, INDIA

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Wilson facies, facetious smile, dysarthria, dystonia-parkinsonism

Samuel A K Wilson Brain, 1912 John N Cumming Brain, 1948 John Walshe Am J Med, 1956

Copper: Role and transport • Active redox (cuprous - cupric): enzymatic activity; toxicity • No free copper • Tightly controlled copper homeostasis Transport of dietary copper 15% of dietary Enterocyte Portal vein Liver copper retained 4 in the body 3 Dietary copper 1 2 2-5 mg / day 4 85% of dietary 1. Non-specific metal transporters copper excreted in bile 2. ATP7A / Menke’s protein (Cu -transporting ATPase) 3. CTR1 transporter 4. ATP7B / Wilson ATPase (Cu-transporting ATPase) Robert EA and Cox DW. Wilson Disease. In: Zakim and Boyer's Hepatology: A Textbook of Liver Disease, 2011; Huster D. Best Pract Res Clin Gastroenterol, 2010

Prevalence and symptoms • Rare (prevalence 1:30,000) • Affecting children and young adults • Autosomal recessive, ATP7B gene • Chronic copper toxicity • Fatal if untreated Fleeting Jaundice Extrapyramidal Brain Liver Hemolytic Anemia Neuropsychiatric Liver Cirrhosis Fulminant Liver Failure Osseomuscular 6

3 years on Penicillamine

Wilson Disease • Diagnosis • Genetics • Treatment

Challenge: Early diagnosis Normal 7 year old 6 year old 3 year old Wilson disease 75% of patients with Wilson disease may go undiagnosed and die of the disease Scheinberg IH. Penicillamine in Wilson’s disease. Lancet 1982 Coffey AJ, Durkie M, Hague S, et al. A genetic study of Wilson’s disease in the UK. Brain 2013

Diagnosis of Neurological Wilson Disease

Diagnosis of Neurological Wilson disease Step 1 Identify the typical Neurological Disorder Step 2 Establish as a multi-systemic disorder Step 3 Establish it as a familial disorder Aggarwal and Bhatt. Neurological Wilson disease. In: Clinical and Translational Perspectives in Wilson Disease. Editors: Kerkar N, Roberts E, Elsevier, pp, 195-214, 2018

Movement Disorder Phenocopy Patient 1 Step 1 Identify the typical Neurological Disorder Patient 2 Step 2 Establish as a multi- systemic disorder Tremor, ataxia, dystonia Step 3 Establish it as a familial disorder Dystonia, OMD, poor axial control

Patient 3 Patient 4 Patient 5 Mixed movement disorder -Stereotype, Chora, Dystonia, OMD, poor axial control

Cognitive and Behavioural Phenocopy Patient 1 Step 1 Identify the typical Neurological Disorder Step 2 Establish as a multi- Patient 2 systemic disorder Step 3 Establish it as a familial disorder

Patient 3 Utilisation behaviour Patient 4 Stereotype

Step 1 Identify the typical Neurological Disorder Step 2 Establish as a multi- systemic disorder Step 3 Establish it as a familial disorder Kayser - Fleischer rings Aggarwal A, Bhatt M, BMJ 2009

Step 1 Movement disorder phenocopy Step 1 • Mixed movement disorder Identify the typical • Early and prominent axial Neurological Disorder • WD facies • KF rings • Cognitive and Behavioural problems Step 2 Establish as a multi Cognitive and behavioural phenocopy systemic disorder • WD facies • KF rings • Associated Movement disorders Step 3 Establish it as a familial disorder Aggarwal and Bhatt. Neurological Wilson disease. In: Clinical and Translational Perspectives in Wilson Disease. Editors: Kerkar N, Roberts E, Elsevier, pp, 195-214, 2018

Liver Fleeting Jaundice Hemolytic Anemia Step 1 Liver Cirrhosis Identify the typical Neurological Disorder Fulminant Liver Step 2 Establish as a multi systemic disorder Step 3 Establish it as a familial disorder Bones Aggarwal and Bhatt. Neurological Wilson disease. In: Clinical and Translational Perspectives in Wilson Disease. Editors: Kerkar N, Roberts E, Elsevier, pp, 195-214, 2018

Step 3 Step 1 Identify the typical Neurological Disorder • Family history of WD Step 2 • Family history of unexplained Establish as a multi neurological, liver or osseomuscular systemic disorder symptoms • Family history of unexplained deaths Step 3 Establish it as a familial Mutational analysis conforming WD disorder Aggarwal and Bhatt. Neurological Wilson disease. In: Clinical and Translational Perspectives in Wilson Disease. Editors: Kerkar N, Roberts E, Elsevier, pp, 195-214, 2018

Diagnosis of Neurological Wilson disease Step 1 Identify the typical Neurological Disorder Step 2 Establish as a multi systemic disorder Step 3 Establish it as a familial disorder Aggarwal and Bhatt. Neurological Wilson disease. In: Clinical and Translational Perspectives in Wilson Disease. Editors: Kerkar N, Roberts E, Elsevier, pp, 195-214, 2018

MRI brain T2W Normal Caudate, putamen Caudate, putamen, Cerebellum (rare) Thalamus GP, thalamus Midbrain: Giant Panda Cortical Changes Pons Pons Gupta S, et al. 19th Intl Congress of Parkinson Disease & Movement Disorders, San Diego, USA, 2015.

⎬ Laboratory tests • 5% patients have normal ceruloplasmin • Ceruloplasmin falsely increased in: • Laboratory tests - Low serum ceruloplasmin Hepatitis and acute inflammation • - High 24-urinary copper excretion • Ceruloplasmin falsely reduced in: - High liver copper (dry weight) Carriers of WD gene (70X > patients) • Hypo-proteinemic states • Newborns • • 24-hour urine Cu excretion falsely elevated Hepatitis • Cholestatic syndromes • Biliary cirrhosis • 1 Roberts, EA & Schilsky, M. Diagnosis and treatment of Wilson disease: An update. Hepatology, 2008 2 2 Ferenci, P, et al. Diagnosis and phenotypic classification of Wilson disease. Liver International, 2003

Wilson Disease • Diagnosis • Genetics • Treatment

Genotypic variability ATB7B protein with functional domains ATP7B gene (ATP7Wilson) • On chromosome 13q14.3 • Large gene: 80 kilobases, 21 exons Wilson disease • Mutations of ATP7B gene - Missense (57%); small deletions / insertions (28%); nonsense (7%); splice site mutations (8%) • > 600 mutations spread over entire gene + promoter region • Autosomal recessive • Most patients are compound heterozygotes Schmidt HH. Role of genotyping in Wilson’s disease. J Hepatol, 2009.

Mutational pattern of various regions in India and p.C271*: The common Indian mutation Hatched areas = regions in India where mutation p.C271* has been identified. Aggarwal et al, 2013, Gupta et al., 2005; Kumar et al., 2005; Santhosh et al., 2006; Gupta et al., 2007b; Kumar et al., 2007

Regional mutational pattern • Whole gene sequencing - 98% mutation detection • Regional variation in dominant mutations Table: High frequency regional mutations Dominant Allelic Region Exon mutation Frequency Europe, North p.H1069Q 14 30-70% America, S Brazil c.3402delC 8 Central Brazil 47.5% p.L708P 15 China p.R778L 8 30-49% India p.C271* 2 9-20% Aggarwal A, et al. Ann Hum Genet 2013; Bem RS , et al.Arq Neuropsiquiatr 2013; Coffey AJ, et al. Brain 2013; Ferenci P. Hum Genet 2006; Deguti MM et al. Human Mutat 2004

Phenotypic variability • Age of onset • Disease severity • Disease presentation - Early-onset hepatic disease - Late-onset neurological disease + subclinical or overt liver involvement • Intra-familial variability Causes • Type and location of the ATP7B mutation - Phenotype in nonsense and frameshift mutations is severe • Other proposed mechanisms - Genetic polymorphisms in ATP7B - Modifier genes: Genes involved in fat and cholesterol metabolism - Role of COMMD1 unclear - Yet undefined factors

Why studying genotype - phenotype correlation challenging? • Genotypic variability • Phenotypic variability • Most mutations are rare

Establishment of first stable human ATP7B knockout hepatoma cell line • HepG2 (human hepatoma cell line) used to create the ATP7B KO cell line • Exon 8 of ATP7B gene spliced by zinc finger nucleases (ZFN) ATP7B gene (exons boxed) Exon 8 blown up Splicing exon 8 (ZFN binding sites boxed) Nucleotide sequence & codons of wtATP7B Nucleotide sequence of KO cell (both chromosomes) 29 Chandhok G, et al. PloS ONE, 2014

Functional analysis of the human ATP7B knockout cell line Different ATP7B mutants showed different copper sensitivity Chandhok G, et al. Functional analysis and drug response to zinc and D-penicillamine in stable ATP7B mutant hepatic cell lines. World J Gastroenterol, 2016

Wilson Disease • Diagnosis • Genetics • Treatment

Neurological Wilson disease is reversible

15 year old 13 year old 11 year old Challenge: Adequate treatment

Treatment options - Low copper diet: Neither necessary nor sufficient - Prevent GI copper absorption - Zinc - Copper chelators - Penicillamine - Trientine - Ammonium tetrathiomolybdate - British antilewisite (BAL) - Liver transplant: Curative - Fulminant liver failure - Decompensated cirrhosis - Intoler ance to copper chelators (rare) - Symptomatic treatment Aggarwal A, Bhatt M. The pragmatic treatment of Wilson’s disease.Movement Disorders Clinical Practice 2014; Aggarwal and Bhatt. Advances in treatment of Wilson disease. Tremor Other Hyperkinet Mov 2018