Other common signs are hip dislocation(s), a tendency to hold the head to one side (torticollis), contractures (tightness) in the hips, knees and elbows and notable ‘bendiness’ or ‘hyperlaxity’ of the hands and feet.
Sometimes the first signs are only noted after a few months, when babies are observed to have poor head control or have a delay in achieving motor milestones, such as sitting unaided, crawling or walking.
Can a child with UCMD learn to walk?
The severity of this condition varies greatly from person to person. Some children learn to walk but may lose this ability over time. Some children with UCMD may have the ability to walk on their knees only, while other children may not have the ability to walk independently at all.
What other physical effects might UCMD have on a child?
As the muscles are weak and mobility is limited, the child may be born with – or develop – joint ‘contractures’. This means that the muscle tendons tighten up and the child is unable to move the limbs or the joints as freely as a healthy child would. Physiotherapy can help prevent or slow the progression of these contractures, so it is helpful for parents to work with a physiotherapist, soon after diagnosis, to establish a programme of exercises for their child to do daily at home.
Hips are commonly affected by contractures and may sometimes be dislocated. Children with UCMD should be assessed by an orthopaedic specialist with expertise in muscle-wasting conditions, ideally working as part of a multi-disciplinary team alongside a paediatric neurologist and a physiotherapist. Some children may require treatment with a splint or, in some rare cases, surgery.
Most children with UCMD also develop a curvature of the spine (scoliosis). This should be monitored in a specialist spinal clinic and may require a spinal brace to improve posture and slow deterioration of the curvature. Surgical intervention (scoliosis surgery) might be needed in some cases.
As collagen VI is also normally present in the skin, children with UCMD have a tendency for scars to heal slowly or become thickened and elevated (keloid formation).
Is UCMD progressive and is it life-limiting?
In the first few years, the condition is fairly stable and the child usually appears to gain strength and achieve motor milestones, albeit delayed. Over time, and particularly with increased growth during puberty, children typically demonstrate more difficulty walking. Children may also experience loss of independent walking as early as seven years of age or as late as the late teenage/early adult years (in those children with the ‘intermediate’ form of the condition).
Children experience breathing problems while sleeping because the muscles that assist breathing are affected. It is essential, therefore, to monitor lung function on a regular basis by performing respiratory function tests; overnight ‘sleep studies’ are also regularly required. Night-time breathing problems can also cause children to feel tired during the day, have headaches on waking in the morning, have a loss of appetite and lose weight.
A decrease in lung function can also result in frequent chest infections. If these signs are present, or if the level of oxygen recorded during an overnight sleep study is not satisfactory, children need to be referred to a respiratory specialist to initiate night-time non-invasive ventilation (NIV). This entails a special facial or nasal mask attached to a small machine that pumps air into the lungs and maintains adequate ventilation. It may also be needed when children develop chest infections.
Another problem frequently encountered by children with UCMD after the first few years of life, is difficulty feeding. This can result in prolonged mealtimes and failure to gain weight normally. For this reason, it is essential to monitor weight and height to ensure children with UCMD receive enough food and energy.
Some children with UCMD may need to take nutritional supplements. A small surgical procedure called a gastrostomy can be performed, which entails inserting a tube directly into the stomach. Gastrostomy tube-feeding ensures people with UCMD receive an adequate level of nutrition when they cannot consume sufficient calories orally.