What is CMD
Congenital myotonic dystrophy is a life limiting condition that affects up to 1 in 47619 live births.
Congenital myotonic dystrophy (CMD) is an autosomal dominant neuromuscular disorder with multisystem involvement. It is a subtype of myotonic dystrophy type 1. Features include severe hypotonia and generalized muscle weakness; myotonia is classically absent in infancy.
What is the life expectancy of someone with congenital myotonic dystrophy?
Lifespan is into adulthood but shortened, 25% of patients die before 18 months of age and 50% die before the mid-30s. The Younger the age of onset, the more severe the muscle weakness, and cardiac arrhythmias which are associated with increased risk of death.
Children born with congenital myotonic dystrophy often have problems breathing as soon as they are born and may need help to breathe, using a ventilator. Suction may also be necessary to remove any secretions in their lungs. Breathing problems may continue, and can be very severe and life-threatening.
Babies often have swallowing and therefore feeding difficulties and may need a feeding tube (nasogastric tube) or – at times of illness – a drip to help with feeding.
Children with congenital myotonic dystrophy may have ‘floppy baby syndrome’, which means they have difficulty moving their arms, legs and head.. This usually improves with age. It is important that they have physiotherapy from a very young age to help with breathing, and to encourage movement and strength. The child may also have poor head control and, often, facial weakness. They may lack facial expression, simply because they may be unable to make the usual range of facial movements. This may improve with time.
Older children with congenital myotonic dystrophy tend to have poor concentration and tire easily. The motor milestones (physical achievements, such as sitting unaided) and the intellectual milestones tend to be delayed. They may have difficulties with speech, particularly with clear pronunciation.
Some may have a squint, and very occasionally they may have impaired vision. They commonly have club feet (talipes), or twisted feet. This may be mild or severe and will improve with physiotherapy. The more severe form, however, will require corrective surgery. Physiotherapy, with passive stretching, and in some cases, special shoes, walking aids and callipers may be needed. Children with the condition may need to use a wheelchair.
The children sometimes take longer to control their bladder and bowels. Bladder control usually improves, however bowel problems – especially constipation – may persist, owing to problems with the muscle of the bowel they may have more trouble with other body functions than they do with their muscles. A symptom that may appear to be totally unrelated may in fact be connected to their condition. It is important that health professionals treating them are aware of the wide range of associated problems.
Will the condition improve?
The symptoms of the condition may improve during childhood, but are likely to deteriorate later in life.
