What is Chorea-acanthocytosis ChAc

Chorea-acanthocytosis (ChAc) is a rare, progressive neurodegenerative disorder characterized by involuntary movements (chorea) and the presence of abnormally shaped red blood cells called acanthocytes. It is a multisystem condition primarily affecting the brain's basal ganglia, leading to significant motor, cognitive, and psychiatric challenges.

What causes Chorea-acanthocytosis?

Chorea-acanthocytosis is caused by mutations in the VPS13A gene, which provides instructions for making the protein chorein. While the exact function of chorein is still being researched, it is known to be critical for the health of neurons in the brain. Chorea-acanthocytosis follows an autosomal recessive inheritance pattern, meaning an individual must inherit two copies of the mutated gene—one from each parent—to develop the condition.

What are the primary symptoms of Chorea-acanthocytosis?

The clinical presentation of Chorea-acanthocytosis is complex, typically emerging between the ages of 20 and 40. Key features include:

• Involuntary movements: Chorea (jerky, dance-like movements) or dystonia, particularly involving the mouth, tongue, and limbs.


• Feeding difficulties: Often characterized by "feeding dystonia," where the tongue protrudes during eating, sometimes leading to self-mutilation of the lips or tongue.


• Neurological changes: Progressive cognitive decline, personality changes, and psychiatric symptoms like depression or obsessive-compulsive behavior.


• Physical signs: The presence of acanthocytes (spiky red blood cells) in the blood, though these are not always present in every blood sample.

How common is Chorea-acanthocytosis?

Chorea-acanthocytosis is an extremely rare disorder with an estimated prevalence of less than 1 in 1,000,000 people worldwide. Because the symptoms overlap with other movement disorders like Huntington’s disease, it is frequently underdiagnosed. At DiseaseMaps.org, we currently support a small community of 6 individuals living with Chorea-acanthocytosis who share their unique experiences with this rare diagnosis.

How is Chorea-acanthocytosis differentiated from other diseases?

While Chorea-acanthocytosis shares movement symptoms with Huntington’s disease, it is distinct due to the presence of acanthocytes, high levels of serum creatine kinase, and its specific genetic markers. Unlike some other neurodegenerative conditions, it specifically manifests with severe oromandibular dystonia, which is a hallmark clinical indicator.

Next steps

• Consult a neurologist specializing in movement disorders for genetic testing and clinical evaluation.


• Connect with the Chorea-acanthocytosis community at DiseaseMaps.org to share resources and support.


• Request a referral to a metabolic or genetic specialist to discuss the latest clinical literature and potential research opportunities.

Medical disclaimer: This information is for educational purposes only and does not replace professional medical advice, diagnosis, or treatment.

References

• NIH Genetic and Rare Diseases Information Center (GARD): Chorea-acanthocytosis


• Orphanet: Chorea-acanthocytosis (ORPHA:164)


• OMIM (Online Mendelian Inheritance in Man): #200150


• National Institute of Neurological Disorders and Stroke (NINDS)