What is ALSP or Adult-onset leukoencephalopathy with axonal spheroids and pigmented glia?

ALSP is a rare adult onset autosomal dominant disorder characterized by changes to certain parts of the brain. As the disorder name indicates, the individual will experience leukoencephalopathy, which is damage to the white matter of the brain, and damage to the axons which is caused by swellings called spheroids. This damage to the myelin and axons contributes to many of the neurological signs and symptoms seen in people with this condition. This condition is also known as Hereditary diffuse leukoencephalopathy with spheroids (HDLS), and CSF1R-related leukoencephalopathy.

What Are the Symptoms?

  • Personality changes
    • Loss of social inhibitions and depression are some of the earliest symptoms of HDLS
  • Memory loss
  • Loss of impulse control, self-monitoring and focus
  • Mild seizures
  • Dementia
  • Difficulty walking
  • Movement abnormalities known as Parkinsonism:
    • Unusually slow movement
    • Trembling
    • Muscle stiffness

How Do You Get ALSP?

This disorder is caused by mutations in the CSF1R gene. This gene provides instructions for making a protein called colony stimulating factor 1 receptor. This protein contributes to the growth of microglial cells. Further research is needed to determine how these gene mutations cause the symptoms.

How Is ALSP Diagnosed?

It is diagnosed through evaluation of the symptoms the individual is experiencing, genetic testing, and MRI. Diagnosis is confirmed by identification of a heterozygous pathogenic variant in the CSF1R gene.

Is There a Treatment?

Bone marrow transplant is a potential treatment for ALSP for eligible patients. There may also be clinical trials for potential new therapies listed on clinicaltrials.gov.

Helpful Resources


Sisters’ Hope Foundation


Genetics Home Reference

Gene Reviews

Leukodystrophy Care Network