Jeremy Ross Parr1, Morag Jane Andrew2, Maria Finnis2, David Beeson3, Angela Vincent3, Sandeep Jayawant2. 1. Institute of Neuroscience, Newcastle University, Newcastle Upon Tyne, UK Department of Paediatrics, University of Oxford, Oxford, UK. 2. Department of Paediatrics, University of Oxford, Oxford, UK. 3. The Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK.
Abstract
OBJECTIVE: To ascertain the frequency of childhood myasthenia in the UK. Specifically, we aimed to identify the detected incidence of autoimmune myasthenia and the detected prevalence of genetically confirmed congenital myasthenic syndrome (CMS) in children. METHODS: All children under 18 years of age on 31 December 2009 with a confirmed CMS genetic mutation were identified by the only UK laboratory undertaking CMS genetic testing. All cases with positive acetylcholine receptor (AChR) and muscle specific kinase (MuSK) receptor antibodies in the 5 years between 2003 and 2007 inclusive were identified by the testing laboratories. UK census data from 2001 were used as the denominator for analyses. RESULTS: The UK detected prevalence of genetically confirmed CMS was 9.2 per million children under 18 years of age. CMS was equally prevalent in girls and boys. CHRNE, RAPSN and DOK7 were the most commonly identified mutations. Prevalence varied across geographical regions in England (between 2.8 and 14.8 per million children). The mean incidence of antibody-positive autoimmune myasthenia was 1.5 per million children per year over the period of the study. Girls were affected more frequently than boys; this difference persisted across the age range. Antibodies were identified during the neonatal period in 17 children. CONCLUSIONS: This laboratory based study shows that childhood myasthenia is very rare. This condition is treatable, and these definitive detected incidence and prevalence data can be used to help plan diagnostic and supporting services for affected children and their families, and maximise research opportunities. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
OBJECTIVE: To ascertain the frequency of childhood myasthenia in the UK. Specifically, we aimed to identify the detected incidence of autoimmune myasthenia and the detected prevalence of genetically confirmed congenital myasthenic syndrome (CMS) in children. METHODS: All children under 18 years of age on 31 December 2009 with a confirmed CMS genetic mutation were identified by the only UK laboratory undertaking CMS genetic testing. All cases with positive acetylcholine receptor (AChR) and muscle specific kinase (MuSK) receptor antibodies in the 5 years between 2003 and 2007 inclusive were identified by the testing laboratories. UK census data from 2001 were used as the denominator for analyses. RESULTS: The UK detected prevalence of genetically confirmed CMS was 9.2 per million children under 18 years of age. CMS was equally prevalent in girls and boys. CHRNE, RAPSN and DOK7 were the most commonly identified mutations. Prevalence varied across geographical regions in England (between 2.8 and 14.8 per million children). The mean incidence of antibody-positive autoimmune myasthenia was 1.5 per million children per year over the period of the study. Girls were affected more frequently than boys; this difference persisted across the age range. Antibodies were identified during the neonatal period in 17 children. CONCLUSIONS: This laboratory based study shows that childhood myasthenia is very rare. This condition is treatable, and these definitive detected incidence and prevalence data can be used to help plan diagnostic and supporting services for affected children and their families, and maximise research opportunities. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
Authors: Pedro M Rodríguez Cruz; Michal Al-Hajjar; Saif Huda; Leslie Jacobson; Mark Woodhall; Sandeep Jayawant; Camilla Buckley; David Hilton-Jones; David Beeson; Angela Vincent; Maria Isabel Leite; Jacqueline Palace Journal: JAMA Neurol Date: 2015-06 Impact factor: 18.302