Hunter Syndrome: Causes, Symptoms, Diagnosis and Treatment

Also called mucopolysaccharidosis II or (MPS II), it is a rare disease transmitted between families. In general, it only affects children.

Their bodies can not break down a type of sugar that builds bones, skin, tendons, and other tissues. These sugars accumulate in your cells and damage many parts of the body, including the brain. What happens exactly is different for each person.

When your child has Hunter syndrome, you can do things to help him play, have friends, and do some things that other children do, although it may seem different from his friends.

Although there is no cure for Hunter syndrome, there are ways to help control it and live with the symptoms.


Children with the disease can not produce a specific protein because there is a problem with a small piece of their DNA, called a gene, that comes from their mother.

A father with Hunter syndrome will pass the problem gene to his daughter, but she will not get the disease unless she also gets the gene from her mother.

It is possible but doubtful that someone could develop Hunter syndrome without anyone in their family having it.



When Hunter syndrome affects the brain, approximately 75% of the time, symptoms usually appear between 18 months and four years of age.

They start about two years later when the disease is milder.

Hunter syndrome usually affects the appearance of the child:

  • Big, round cheeks
  • Wide nose.
  • Thick lips and a giant tongue.
  • Thick eyebrows.
  • Bighead.
  • Slow growth
  • Thick and problematic skin.
  • Short, broad hands with rigid and curly fingers.

You will probably have these symptoms:

  • Problems in the joints that make it difficult to move.
  • Numbness, weakness, and tingling in your hands.
  • Many coughs, colds, sinusitis, and throat infections.
  • Breathing problems, including pauses in breathing at night or sleep apnea.
  • Hearing loss and ear infections.
  • Problems walking and weak muscles.
  • Intestinal problems, such as diarrhea.
  • Heart problems, including damaged heart valves.
  • Liver and spleen enlarged.
  • Bone thickening.

When a child’s brain is affected, it is likely to have:

  • Problems to think and learn when you are between 2 and 4 years old.
  • Issues to talk about.
  • Behavioral issues, such as difficulty staying still or aggressiveness.

Children who have Hunter syndrome are usually cheerful and affectionate, despite the problems it can cause.


If the doctors can not find another explanation for your child’s symptoms, they will evaluate Hunter’s syndrome by checking if:

  • High levels of that specific sugar in your urine.
  • How active is the “missing” protein in your blood or skin cells?
  • The abnormal gene.

After doctors are sure that it is Hunter syndrome, it is a good idea to also inform family members about the gene problem.

If you are a pregnant woman and you know you have the gene or already have a child with Hunter syndrome, you can determine if the baby you are carrying is affected.

Talk to your doctor about the tests early in your pregnancy.


Early treatment can prevent some long-term damage.

Enzyme replacement therapy (ERT) can help delay the disease in children with milder Hunter syndrome. It replaces the protein that your body does not produce. TRE can help improve:

  • Walk, climb stairs, and the ability to keep abreast in general.
  • Movement and rigid joints.
  • Breathing.
  • Increase.
  • Hair and facial features

TRE is the first treatment for children whose brains are not affected. It does not slow the disease in the brain.

Transplants of bone marrow and umbilical cord blood

These transplants bring cells to your child’s body that can hopefully produce the protein that is being lost.

The new cells come from a bone marrow donor whose cells match your child’s or newborn babies’ umbilical cord blood stem cells.

Both treatments are high risk. In general, they are used only if other treatments are not possible. Neither has it been shown to help when the brain is affected.

Research is being done to find effective treatments for children with severe Hunter syndrome.

Because many different parts of your child’s body may be affected, you may need to see several doctors to help you manage the condition, including:

  • Specialist in the heart.
  • Specialist in ear, nose, and throat.
  • Ophthalmologist.
  • Lung specialist
  • A mental health professional.
  • Neurologist.
  • Speech therapist

Therapies, care, and medications:

  • Occupational therapy can help you make changes at home and school to make it easier to get around and do things.
  • Medications such as melatonin can help you sleep.
  • Please keep your child healthy and allow him to live a meaningful and rewarding life.
  • Please include it in family activities as long as it is safe.
  • Begin stretching exercises and early range of motion to keep your joints flexible.
  • Choose large toys that are easy to grasp and hold on to and will not be damaged by chewing.
  • Talk with other children (or their parents) about how to interact with your child.
  • Help him learn as much as he can while his brain functions well.
  • Some children with less severe Hunter syndrome grow and live long lives.

They will go through puberty like other teenagers and can have children. However, heart disease and breathing problems can still cause problems.

Children with severe Hunter syndrome are less likely to reach adulthood.

Their brains will stop working slowly, and eventually, they will need special care so they are comfortable.

Parents of other children with Hunter syndrome are a great resource to understand what is happening, share their feelings and get ideas on how to live with the condition.