Chorea-acanthocytosis

Chorea-acanthocytosis is a rare hereditary neurodegenerative disease, with only an estimated five hundred to one thousand people affected worldwide. It is caused by mutations in both copies of the VPS13A gene, which codes for the protein chorein, and is usually inherited in an autosomal recessive way, though a few dominant cases are reported. It is one of four conditions grouped as neuroacanthocytosis, named for thorny red blood cells called acanthocytes seen under the microscope. Symptoms usually begin around age thirty-five and include involuntary movements such as chorea, tics and dystonia, parkinsonism in some patients, poor balance, behavioral and personality changes, memory problems, trouble swallowing and speaking, and seizures, which in about a third of patients are the first sign. Blood tests show raised creatine kinase, and diagnosis is confirmed by reduced chorein and genetic analysis. The disease is incurable and leads to early death.