What is 4H Syndrome?

4H Syndrome is short for hypomyelination with hypogonadotropic hypogonadism and hypodontia and is a rare genetic disorder that affects the nervous system. Hypomyelination means that there is a lack of myelin in the central nervous system. Hypogonadotropic hypogonadism means that normal puberty development is absent because the central nervous system is not able to initiate it properly. Finally, hypodontia means that not all teeth are present.

What Are the Symptoms?

Symptoms may include:

  • Problems with balance and walking
  • Clumsy, fall frequently
  • Abnormal gait
  • Stiff limbs
  • Uncontrolled muscle contractions which can lead to dystonia
  • Ataxia
  • Tremor
  • Vision problems
  • Speech problems
  • Learning disabilities
  • Abnormal tooth development
  • Small size
  • Vision problems
  • Atypical puberty

How Do You Get 4H Syndrome?

This disorder is most likely inherited in an autosomal recessive manner. 4H is caused by mutations in one of three genes: POL3RA, POL3RB, and POLR1C.

How Is 4H Syndrome diagnosed?

It is diagnosed through examination of physical symptoms, MRI and genetic testing.

Is There a Treatment?

There is no known cure and treatment is symptomatic.

Helpful Resources

United Leukodystrophy Foundation

Children’s Hospital of Philadelphia

Leukodystrophy Care Network