Multiple Sclerosis… or APBD?

Download the MS… or APBD? Fact Sheet

What is Adult Polyglucosan Body Disease (APBD)?

• a rare glycogen storage disease type IV caused by mutations in the glycogen branching enzyme gene
• 40 known pathogenic variants in GBE1 gene
• inherited in an autosomal recessive pattern
• characterized by a deficiency of glycogen branching enzyme, resulting in the accumulation of polyglucosan bodies in muscles, nerves, and other tissues
• the gene involved in causing APBD is the same gene at the center of Andersen’s Disease (glycogen storage disease type IV), a severe liver condition affecting infants

What is the scope?

• to date, 200 diagnosed patients worldwide
• affects men and women in equal proportions
• diagnosed most frequently in Ashkenazi Jewish populations, but it is pan-ethnic

How is it diagnosed?

• GBE assay (blood test)
• sequencing genomic DNA/messenger RNA (saliva test)
• histologic examination of sural nerve biopsy

APBD symptoms

• Symptoms and severity can vary greatly from one person to another
• Develop around the fifth decade of life
• Diminish quality of life by interfering with the ability to work, mobility, and independence– A – Adult onset, Ashkenazi Jewish ancestry
  Although most patients are of Ashkenazi Jewish descent, it is pan-ethnic– P – Peripheral neuropathy
  Numbness, weakness, stiffness, and pain in the lower limbs, and sometimes the upper limbs

  – B – Bladder dysfunction
  An increased need to urinate and urgency to urinate, progressing to a complete loss of bladder control

  – D – Decreased energy
  Overwhelming need to rest and sleep throughout the day

Why is APBD confused with MS?

• MS has a similar adult onset
• MS has some of the same symptoms as APBD
• Physicians often are not aware of APBD clinical and imaging features and mistake the disease for MS and other neurodegenerative conditions

What can you do?