Canavan Disease

Canavan disease is part of a family of conditions called leukodystrophies. Rare, gradual, metabolic, genetic disorders known as leukodystrophies can have far−reaching effects on nervous system structures beyond the brain and spinal cord (peripheral nerves). There are at least ten different types of leukodystrophy, each of which is caused by an irregularity affecting a different gene and leading to abnormal development of a different chemical found in the brain's white matter. Nerve fibers make up the white matter of the brain. Myelin is a fatty membrane composed of proteins and lipids that protects many nerve fibers. The myelin sheath is a protective covering for the nerve fibers that also serves as an insulating material and facilitates faster signal transmission. Different types of leukodystrophy affect different components of the myelin sheath, resulting in a wide spectrum of neurological symptoms.

What is Canavan Disease?

Brain disorders like Canavan disease are uncommon and often caused by genes. The neurodegenerative nature of the disease means that the abnormality in the brain worsens with time. The brain becomes spongy and poorly functions when a crucial substance is missing. Leukodystrophies are a category of disorders that includes Canavan disease. These diseases are progressive, uncommon, hereditary conditions that manifest in various ways throughout the nervous system.

What are the Symptoms of Canavan Disease?


Affected newborns also exhibit delays in attaining developmental stages (e.g., standing or sitting unsupported), and most never walk independently. The increasing loss of skills requiring the synchronization of mental and physical activity (motor coordination regression) and developmental delays also become evident throughout infancy. Most afflicted newborns learn to grin, giggle, lift their heads and engage socially.


Seizures, sleep disturbances, feeding problems, nasal regurgitation, and reflux (the backflow of stomach acid into the esophagus) are sometimes accompanied by vomiting. Degeneration of the nerve endings of the eye sockets (optic nerve endings) that sends impulses from the wracking membrane lining the eyelids (retina) to the brain is also common among children with Canavan illness (optic atrophy). The visual response may decrease as a result of optic atrophy. Hearing loss is uncommon; therefore, hearing is usually unaffected.


If left untreated, hypotonia in babies may progress to spasticity, a disorder characterized by involuntary muscle spasms that cause sluggish, rigid motions of the legs. Decerebrate rigidity is a condition in which a person's arms, limbs, fingertips, and toes become stiff and unable to move. Canavan disease is a progressive illness that may lead to fatal consequences, albeit the rate at which each individual's case develops and how severe those problems are can vary widely. Some infants have life−threatening difficulties, while others make it to adulthood.

What are the causes of Canavan Disease?

A recessive genetic disorder emerges when an affected individual receives two copies of a defective gene from each parent. A carrier is someone who carries the disease but does not exhibit any symptoms due to receiving one human gene and a gene for the disease. Each pregnancy involving two carrier parents carries a 25% chance of producing an affected child. There is a 50% chance that each pregnancy will result in a carrier child, just like the parents. A child has a 25% chance of inheriting normal genes for that trait from both parents. Both sexes face an equal threat.

What is the Diagnosis of Canavan Disease?

Infants are displaying symptoms typical of Canavan illness raise suspicion about the diagnosis. Comprehensive clinical assessment results, including a complete medical history and a battery of specialized testing, may help confirm a diagnosis. Gc spectrometry, a tool that may identify increased amounts of NAA in the urine, may be used in such examinations. NaN3 acetyltransferase activity is also increased in the plasma and spinal fluid (CSF). To detect an aspartoacylase deficit, researchers may analyze cultured fibroblasts, cells found in the skin's connective tissue.

Additionally, white blood cells cannot produce aspartoacylase. Amniocentesis, performed between 16 and 18 weeks of pregnancy, allows for detecting Canavan disease in the mother's bloodstream by evaluating the amount of NAA in the amniotic fluid around the growing baby. Chorionic villus collection (CVS) allows for prenatal diagnosis if both parents possess identified ASPA gene mutations by removing a sample of placenta cells at 10−12 weeks of gestation for mutation investigation.

What is the Treatment of Canavan Disease?

Canavan disease therapy is tailored to patients by focusing on their unique condition manifestations. Some pain relief might be achieved by providing supportive care. Posture and language skills may benefit from physical therapy and early intervention. Feeding tubes may help patients get the nourishment and fluids they need if they have trouble swallowing. Anti−seizure drugs are an option for those dealing with seizures. Gene therapy as a potential treatment for children with Canavan illness is the subject of current research. Doctors use gene therapy to introduce functional copies of the gene into their developing nervous systems to treat children with ASPA deficiency. Aspartoacylase, the enzyme necessary to degrade NAA, is produced by the genes that do just that. Symptoms have significantly diminished in children who have been treated with gene therapy. Gene therapy has shown promise as a possible treatment for those with Canavan disease, but further study is needed to confirm its long−term safety and efficacy.

Canavan's illness is untreatable, and no recognized therapy protocol has been established. Effective forms of treatment and support. Some people benefit from physical treatment to enhance their movement skills, while others benefit from educational programs to boost their language abilities. Antiepileptic medicines are used to treat seizures, and a gastrostomy is performed in cases when the patient has trouble swallowing, making it difficult for them to take in enough food or liquids.


Confirmed cases of Canavan illness have been found in infants and young children. The degeneration of myelin, the protective covering of nerve cells in the brain, is due to a lack of an enzyme passed down from generation to generation.