Canavan Disease: Symptoms, Diagnosis, Information

Author: Ian C. Langtree - View Credentials
Published: 1 Apr 2009 - Updated: 28 Jan 2023

Table of Contents:
Synopsis - Definition - Overview - Related Content

Synopsis

Canavan disease is a gene-linked neurological disorder in which the brain degenerates into spongy tissue with microscopic fluid-filled spaces.

Topic Definition

Canavan Disease (CD)

Canavan disease is a gene-linked neurological disorder in which the brain degenerates into spongy tissue with microscopic fluid-filled spaces. Canavan disease has been classified as one of the genetic disorders known as leukodystrophies. Canavan disease causes progressive brain atrophy. There is no cure, nor is there a standard course of treatment. Treatment is symptomatic and supportive. The prognosis for Canavan disease is poor. Death usually occurs before age 10, although some children may survive into their teens and twenties.

Overview

Canavan disease alternate names include: Aminoacylase-2 (ACY2) Deficiency, aspartoacylase (ASPA) Deficiency, Canavan's Leukodystrophy, Spongy Degeneration of the Central Nervous System or Neuroaxis, Van Bogaert-Bertrand Syndrome.

The U.S. Social Security Administration (SSA) has included Canavan Disease (CD) as a Compassionate Allowance to expedite a disability claim.

Canavan disease (CD) is caused by mutations in the gene for an enzyme called aspartoacylase and is a severe progressive inherited (genetic) disorder of the central nervous system (CNS). It is one of the infancy's most common cerebral degenerative diseases; it is a gene-linked, neurological birth disorder in which the brain's white matter degenerates into spongy tissue riddled with microscopic fluid-filled spaces.

Canavan disease is one of a group of genetic disorders known as the leukodystrophies. These diseases cause imperfect growth or development of the myelin sheath, the fatty covering that acts as an insulator around nerve fibers in the brain. Myelin, which lends its color to the "white matter" of the brain, is a complex substance of at least ten different chemicals. Each of the leukodystrophies affects one (and only one) of these substances.

Symptoms of Canavan Disease

Symptoms of Canavan disease, which appear in early infancy and progress rapidly, may include mental retardation, loss of previously acquired motor skills, feeding difficulties, abnormal muscle tone (floppiness or stiffness), and an abnormally large, poorly controlled head.

Paralysis, blindness, or hearing loss may also occur.

Children are characteristically quiet and apathetic.

Although Canavan disease may occur in any ethnic group, it is more frequent among Ashkenazi Jews from eastern Poland, Lithuania, and western Russia and among Saudi Arabians.

Diagnoses

Clinical findings leading up to the diagnosis would include:

• Physical findings include the triad of hypotonia (low muscle tone), macrocephaly (abnormally large head), and head lag in an infant aged three to five months of age or older.
• CT and MRI abnormalities of the cerebral white matter (relatively spared cerebellum and brain stem white matter).
• Urine gas chromatography-mass spectrometry (GC-MS) finding of elevated N-acetylaspartic acid (NAA).

The test to confirm the diagnosis is a full gene sequence analysis of ASPA. Gross deletion/duplication analysis of the entire ASPA gene is performed to detect known and potential novel gross deletions.

Canavan disease causes brain tissue atrophy and cystic cavities resulting in enlargement of the brain and head size. There is no cure, nor is there a standard course of treatment. Treatment is symptomatic and supportive. The prognosis for Canavan disease is poor. Death usually occurs before age 4.

Author Credentials: Ian C. Langtree is a writer, editor, and the founder and Editor-in-Chief of Disabled World, which he established in 2004 as one of the longest-running independent resources for disability news and information. Over more than two decades, he has written and edited thousands of articles on disability rights, health, accessibility, and assistive technology. Drawing on a global perspective shaped by extensive travel and lived experience, Ian is a committed advocate of the Social Model of Disability, the framework developed by disabled activists in the 1970s that focuses on removing societal barriers rather than on individual impairments. His writing is grounded in that framework and in a lasting commitment to disability rights, accessibility, and social inclusion. To learn more about Ian's background, expertise, and accomplishments, visit his full biography.