The four genes so far identified as causing myotubular (MTM) and centronuclear myopathy (CNM), namely MTM1, DNM2, BIN1 and RYR1, can all now be tested for in the UK by Dr Stephen Abbs and his team in the DNA Laboratory of GSTS Pathology, Guy’s & St Thomas’ Hospital, London.
Until recently, patients in the UK would have had their DNA (blood samples) sent to laboratories in France and Germany making the testing a lengthy process and often taking several months before the patient was able to receive any results. The new UK testing facility is currently funded through the NCG Service for Congenital Muscular Dystrophies and Myopathies for the RYR1 gene, and through a grant from the Guy’s & St Thomas’ Charitable Foundation to Dr Abbs and his colleague Dr Heinz Jungbluth, a Paediatric Neurologist and researcher with a special interest in centronuclear myopathy, for all other genes implicated in CNM. This new service means that waiting times for results has now been drastically reduced for UK patients to around 8 weeks.
Dr Heinz Jungbluth, who was involved in discovering some of the genes implicated in centronuclear myopathy, says: “We’re very excited to be able to offer this service and the possibility of a genetic diagnosis to families with a child affected by myotubular and centronuclear myopathy. Achieving a precise genetic diagnosis is the ultimate aim of our assessment, however, a careful review of clinical and muscle biopsy findings remains extremely important to inform the choice of testing, which for some genes is still very laborious even with the most sophisticated techniques currently available. It is therefore important that prior to genetic testing the child is referred to (either by his local Consultant Paediatrician or Paediatric Neurologist) and assessed at a tertiary neuromuscular centre with an expertise in centronuclear and other congenital myopathies, such as the Neuromuscular Service here at the Evelina Children’s Hospital or the Dubowitz Neuromuscular Centre at Great Ormond Street Children’s Hospital. In addition, one or more further genes that cause centronuclear myopathy have yet to be identified as not everyone affected by the condition has a change in one of the four genes we can currently test for, but it is still important that patients with an unconfirmed genetic mutation are known to us, and therefore hopefully involved in future clinical studies to help identify other, even rarer genes associated with MTM/CNM.”
For more general information on the genes which have already been identified in centronuclear myopathy, please read the clinical overview of MTM/CNM on our Myotubular Trust website.
A Genetic Testing Service For NHS Patients And Patients From Abroad
The genetic testing service for patients affected by centronuclear/ myotubular myopathy is free for patients on the NHS and available for a fee for patients from abroad.
For requests for genetic testing in MTM/CNM patients from abroad, a referral letter should be sent to Dr Heinz Jungbluth at the address below, outlining the patient’s salient clinical and muscle biopsy findings in order to allow an informed choice of the appropriate genetic test.
Information about the cost of testing for non-NHS patients can be obtained by contacting the laboratory at the Guy’s Hospital address detailed below.
Senior Lecturer and Consultant in Paediatric Neurology
Department of Paediatric Neurology – Neuromuscular Service
Evelina Children’s Hospital – 6th Floor, Sky
St. Thomas’ Hospital
Lambeth Palace Road
London SE1 7EH
phone 0207 188 3998 (secretary)
fax 0207 188 0851
A copy of the muscle biopsy report, digital images from the muscle biopsy or the original muscle biopsy slides are also very helpful in determining the appropriate test.
The DNA sample for testing should be sent with a copy of the referral letter to:
5th Floor, Guy’s Tower
Great Maze Pond
London SE1 9RT
Phone 020 718 82582
Fax 020 718 87273
Meeting the Needs of Adult Patients
In recognition of the often unmet needs of adults with centronuclear and other congenital myopathies, Dr Jungbluth has also recently established a joint adult congenital myopathy clinic with his colleague Dr Fiona Norwood, Consultant Neurologist with a special interest in neuromuscular disorders at King’ College Hospital. Patients with centronuclear myopathy who would like to be seen in this clinic should be referred either by their GP or local Consultant to:
Fiona Norwood FRCP PhD,
Honorary Senior Lecturer and Lead Clinician
9th Floor Ruskin Wing,
King’s College Hospital,
London SE5 9RS
Tel 020 3299 8343
Fax 020 3299 8358