Myotubular Myopathy
What are the symptoms?
There are at least three different types of this condition. The types are defined by the way in which it has been inherited. The most severe form, which typically affects boys, presents at birth or even before birth, in contrast to the other two and milder forms which present later in childhood. The most severe type is called ‘X-linked recessive’ type and the milder types are called ‘autosomal recessive’ and ‘autosomal dominant’. In all types, but particularly the severe type, the mother may notice a reduction in fetal movements during the pregnancy, or the doctors might have said that there was too much fluid (water) around the baby. The baby may also have a low birth-weight.
At birth, the symptoms are Hypotonia, breathing and swallowing difficulties. In the very severely affected cases, the baby may not survive for more than a few days or weeks. In others, there appears to be slowly progressive muscle weakness that affects the face, limbs and muscles involved in breathing. The affected muscles are weak and cannot function as well as normal (unaffected) muscles. As a result, children may have a variety of symptoms, including drooping of the eyelids, reduced movements of their eyes, drooling, swallowing difficulties and weakness of limbs and trunk. Some children are constipated and this may be as a direct result of the muscles in the gut being affected or caused by poor mobility. Hearing, vision and intelligence are usually unaffected.
The condition may be non-progressive, progress slowly or progress moderately quickly. In general the earlier the onset of the disease the more severe and progressive the disorder appears to be. In the form that presents at birth, there may be life-threatening breathing difficulties and severe hypotonia (floppiness). However, in most cases the disease is only slowly progressive and most patients become weaker in late adolescence or early adult life and may eventually lose the ability to walk. They may also develop droopy eyelids and the muscles that move the eyeballs may also be affected. Occasionally muscle weakness may progress quite rapidly and these patients experience serious breathing problems.
Background
| How is it diagnosed? ![]()