Ataxia with vitamin E deficiency (AVED) leads to the progressive degeneration of the nervous system, resulting in the loss of voluntary movement control (ataxia).
However, early and consistent treatment with vitamin E can help prevent the onset of symptoms. If left untreated, AVED can cause difficulty speaking, loss of sensation in the arms and legs, and decreased visual acuity. Some individuals may also experience intellectual decline, mental issues, or heart problems. Untreated individuals typically experience movement difficulties starting between ages 4 and 18, which worsen over time. Early symptoms often involve hand clumsiness, handwriting problems, and reduced body awareness. Moreover, untreated individuals lose tendon reflexes in their arms and legs. It’s important to note that the type and severity of symptoms can vary significantly from person to person, even within the same family.
AVED is caused by pathogenic (disease-causing) variants in the TTPA gene and exhibits autosomal recessive inheritance. This means that both parents must be carriers to have a 25% chance to have a child with the condition. The risk of being a carrier is based on a person’s ancestry or ethnic background. For example, individuals of Ashkenazi Jewish descent have a 1 in 513 chance to be a carrier.
Other names for this condition are familial isolated vitamin E deficiency, FIVE, Friedreich ataxia phenotype with selective vitamin E deficiency, and Friedreich-like ataxia.
Resources:
National Organization for Rare Disorders
Revised July 2023
