Pediatric myotonic dystrophy

What is pediatric myotonic dystrophy?

Myotonic dystrophy is a rare condition that can cause weakness in the muscles and other parts of the body. Often it causes weakness in the face, neck, arms and legs. Myotonic dystrophy affects different systems in the body and may slowly get worse over time.

Kids with this condition typically experience myotonia. This is difficulty relaxing muscles after they’ve been contracted, for example having trouble opening a closed fist. Children may also have difficulty with certain kinds of movements, such as climbing stairs.

In severe cases, this condition can:

• Affect the brain and cause delays in how a child develops

• Cause problems with the heart and with breathing

• Cause problems with the digestive system

What are the different types of pediatric myotonic dystrophy?

The different types of this condition appear at different ages, but the symptoms are similar.

• Congenital myotonic dystrophy - Children with this form of myotonic dystrophy are born with the condition. At birth, they are weak and may show other symptoms of myotonic dystrophy. Babies may need a breathing tube or a feeding tube, and their brain may have been affected from not getting enough oxygen. This is the most common form among children.

• Childhood and juvenile myotonic dystrophy (DM) - This form of myotonic dystrophy appears during childhood or adolescence. It can be mild or severe. Mild myotonic dystrophy can cause weakness in some muscles. A more severe form will have a stronger effect and can affect more parts of the body.

What are the signs and symptoms of pediatric myotonic dystrophy (DM)?

Signs and symptoms of myotonic dystrophy may include:

• Muscle weakness, including in the face

• Muscle pain, cramps and fatigue

• Curvature of the spine (scoliosis)

• Difficulties with learning

• Difficulties with speaking

• Thyroid disease or diabetes

• Difficulty breathing or eating in babies

• Effects of the eyes, heart, lungs and digestive system

How is pediatric myotonic dystrophy (DM) diagnosed?

Doctors may use the following steps to diagnose myotonic dystrophy in a child:

• Taking a family history

• Seeing if a child can tighten and relax a fist

• Doing a physical exam

• Doing genetic testing to confirm the diagnosis

What causes pediatric myotonic dystrophy?

This condition is caused by a change (mutation) in the genes. It can be passed down from parent to child.

Some parents may have mild symptoms but not know that they have myotonic dystrophy. If a parent has mild symptoms, such as weak hand muscles or difficulties relaxing their hands, they should consider being tested too.

How is pediatric myotonic dystrophy treated?

At Children’s Health, we follow children with this condition to make sure that they get all the care they need. We focus on trying to prevent problems – such as difficulty breathing – from getting worse.

We build a care program tailored to each child and continue to offer support as they grow up.

Your child may be treated by a team of providers that include:

• Occupational (OT) and physical therapists (PT) -who help keep joints and muscles mobile

• Cardiologist - who will check your child’s heart

• Pulmonologist - who will help keep your child’s lungs strong

• Genetic counselors - who might identify a gene that causes myotonic dystrophy

• Physical medicine and rehabilitation specialists

• Nutritionist - to work with your family on diet

• Gastroenterologist - who will work with you to help keep your child’s digestive system working as well as possible.