What is MLC or Megalencephalic Leukodystrophy with subcortical cysts?

MLC is a genetic disorder that impacts brain development and function. While the classic disease type is progressive with symptoms worsening over time, there is an improving disease type where symptoms can improve over time. This disorder is also known as Van der Knaap Syndrome.

What Are the Symptoms?

Symptoms typically appear within the first year of life, including the following:

  • Abnormally large head
  • Seizures
  • Poor muscle movement
  • Stiffness of muscles
  • Muscle spasms
  • Involuntary writhing movements of the limbs
  • Difficulty swallowing
  • Impaired speech
  • Learning difficulties
  • Mental decline

How Do You Get MLC?

MLC is inherited through an autosomal recessive pattern (both parents must be carriers and pass on the genetic mutation to their child). For the classic disease type, MLC is caused by two mutations in either the MLC1 gene or the GLIALCAM gene. The improving disease type, meanwhile, is caused by one mutation in the GLIALCAM gene. Both genes (MLC1 and GLIALCAM) affect the production of the MLC1 protein which helps to regulate the volume of the brain.

How Is MLC Diagnosed?

MLC can be diagnosed in one of two ways. The first is through an MRI scan that will determine if an individual’s brain is swollen or if subcortical cysts have formed below the cerebral cortex. The second is through genetic testing for the mutations in the MLC1 gene or the GLIALCAM gene.

Is There a Treatment?

Unfortunately, there is currently no available treatment, although symptoms can be alleviated through medications and therapies.

Helpful Resources

United Leukodystrophy Foundation

Genetics Home Reference

National Institute of Health

Leukodystrophy Care Network