Spinal muscular atrophy
These are a group of inherited diseases that cause progressive muscle degeneration and weakness. Grouped together, spinal muscular atrophy conditions are the second leading cause of neuromuscular disease.
Approximately four out of every 100,000 people have the condition, and most of the time, it is passed on by a defective gene from both parents.
The most severe form is spinal muscular atrophy (SMA) type I, which is also called Werdnig-Hoffman disease. Infants with SMA type II have less severe symptoms during early infancy, but they become progressively weaker with time. SMA type III is the least severe form of the disease.
For more information on the condition, visit the Spinal Muscular Atrophy Support UK website.
October 2019 update
The muscular dystrophies are a group of inherited disorders that involve muscle weakness and loss of muscle tissue, many of which worsen over time. Muscular dystrophies are inherited conditions, which means they are passed down through families. They may occur in childhood or adulthood.
There are many different types of muscular dystrophy. They include Duchenne and Becker muscular dystrophy, Emery-Dreifuss muscular dystrophy, facioscapulohumeral muscular dystrophy, limb-girdle muscular dystrophy and myotonic dystrophy.
For more information on these conditions, visit the Muscular Dystrophy Campaign website.
You can download free factsheets from the website on neuromuscular conditions, congenital muscular dystrophy, Ullrich muscular dystrophy, Merosin deficient muscular dystrophy, as well as information on steroids and Duchenne muscular dystrophy.
Congenital myopathy refers to a group of muscle disorders which are present from birth or in infancy, and which usually result in weakness. Typically, an infant with a congenital myopathy will be floppy, have difficulty breathing or feeding, and may lag behind other babies in meeting normal developmental milestones, such as turning over or sitting up.
There are currently several different types of congenital myopathy, with some variation in symptoms, complications, treatment options, and outlook. These include, nemaline myopathy, myotubular myopathy, centronuclear myopathy and several other forms.
There is considerable variation in how these conditions present and progress.
Hereditary neuropathies are a group of inherited disorders affecting the peripheral nervous system. The hereditary neuropathies are divided into four major subcategories: hereditary motor and sensory neuropathy, hereditary sensory neuropathy, hereditary motor neuropathy, and hereditary sensory and autonomic neuropathy.
These conditions are rare in childhood. The most common type is also known as Charcot-Marie-Tooth disease. Symptoms of these neuropathies vary according to the type and may include sensory symptoms such as numbness, tingling, and pain in the feet and hands, or motor symptoms such as weakness and loss of muscle bulk, particularly in the lower leg and feet muscles.
The symptoms of hereditary neuropathies may be apparent in childhood or appear in middle or late life. They can vary among different family members, with some family members being more severely affected than others.
Congenital myasthenic syndromes
Congenital myasthenic syndromes (CMS) are a group of inherited neuromuscular disorders which usually cause weakness and fatigue. There are several types and symptoms can be variable.
Symptoms include weakness, especially of the eye, mouth, and throat that may worsen with activity, droopy eyelids, curvature of the spine (scoliosis), and feeding and breathing problems. In most cases, symptoms begin after birth or in early childhood.
There are several known genes responsible for some of these conditions which we can screen for in appropriate cases. There is no specific cure, but some medications can bring about a considerable improvement in most cases.
We also see children with myasthenia gravis, which is similar to CMS, and caused by circulating antibodies to proteins at the nerve. Muscle junction CMS is similar to myasthenia gravis (MG), which is much more common and can sometimes affect children.
Joint diagnostic and advisory clinics for the childhood myasthenias are held monthly by the Oxford team and Dr Stephanie Robb, Paediatric Neurologist, alternating between Great Ormond Street Hospital and Oxford.
Skeletal Muscle Channelopathies
Skeletal muscle channelopathies are rare inherited neuromuscular disorders that include non-dystrophic myotonia and the periodic paralyses. They affect approximately 1 in 100 000 people in the UK.They cause muscle weakness or paralysis or a delay in relaxing muscles (myotonia) that often feels like cramp or the muscle becoming stuck. Sometimes this can be painful.
As these are very rare conditions most general physicians may only see 1 or 2 people with these disorders during their career. Our new multidisciplinary specialist Paediatric clinic has been created to provide a central diagnostic and treatment service that has experience and expertise in managing these conditions. It is directly nationally funded by NHS England to promote equality in health care for rare diseases. If a diagnosis of a channel problem has already been made then you may still be referred to us for advice on management and treatment of your muscle symptoms.