Canavan disease Health Article

Definition

Canavan disease is an inherited condition that affects the breakdown and use (metabolism) of aspartic acid.

Alternative Names

Spongy degeneration of the brain; Aspartoacylase deficiency

Causes, incidence, and risk factors

Canavan disease is inherited as an autosomal recessive trait. It is more common among Ashkenazi Jews than in the general population.

The lack of the enzyme, aspartoacylase, leads to a buildup of material called N-acetylaspartic acid in the brain. This causes the white matter of the brain to break down (deteriorate).

Symptoms

Symptoms usually begin in the first year of life. Parents tend to notice when a child is not reaching certain developmental milestones, including head control.

Symptoms include:

• Abnormal posture with flexed arms and straight legs
• Backflow of food material into the nose (nasal regurgitation)
• Blindness
• Feeding problems
• Increasing head size (macrocephaly)
• Lack of head control when baby is pulled from lying to sitting position (head lag)
• Poor muscle tone, especially of the neck muscles
• Reflux with vomiting
• Seizures
• Severe mental retardation
• Swallowing difficulties

Signs and tests

• Exaggerated reflexes (hyperreflexia)
• Joint stiffness
• Loss of tissue in the optic nerve of the eye (optic atrophy)

Tests:

• Blood chemistry
• CSF chemistry
• Genetic testing for aspartoacylase gene mutations
• Head CT scan
• Head MRI scan
• Urine chemistry

Treatment

Treatment aims to ease the symptoms of the disease. There is no specific treatment.

Support Groups

Additional information and resources are available from:

Canavan Foundation

www.canavanfoundation.org

877-4-CANAVAN

Expectations (prognosis)

With Canavan disease, the central nervous system breaks down. Patients are likely to become disabled.

Death often occurs before 18 months of age. However, some patients live until they are teenagers or, rarely, young adults.

Complications

This is often a fatal disorder. It includes severe disabilities such as:

• Blindness
• Inability to walk
• Mental retardation

Calling your health care provider

Call your health care provider if your child has any symptoms of Canavan disease.