Overview

Canavan disease is a rare and severe genetic disorder that affects the nervous system. It results from a deficiency of an enzyme called aspartoacylase, leading to the accumulation of a substance called N-acetylaspartic acid (NAA) in the brain. This accumulation damages nerve cells, causing neurological symptoms such as developmental regression, intellectual disability, and loss of motor function. There is currently no cure for Canavan disease.

Canavan's disease affects your brain's white matter, a rare genetic disorder. There are a lot of complications when it's the infantile type. It can even result in untimely death. The juvenile type of Canavan disease presents only mild symptoms, such as developmental delays.

As a diagnosis, DNA tests effectively detect if an individual has this genetic disorder. There are a few tests that can even tell if your baby has Canavan disease or not before their birth. This disorder occurs when your brain becomes such as a sponge lacking an important chemical. The brain stops functioning properly due to the lack of that chemical.

Types of Canavan Disease

Canavan disease is a part of Leukodystrophies, another disease group. This group has disorders affecting the brain, nervous system and spinal cord. They are extremely rare genetic disorders, and they get worse as time passes.

Canavan disease typically happens during infancy or early childhood. The most severe is the infantile type. Infantile Canavan disease is also very uncommon, and babies suffering from this disease in their infancy have a shorter life expectancy as they are likely to die in their childhood or adulthood.

The less common is the Juvenile Canavan disease. The symptoms are milder, and children affected by this disease don't have a shorter life expectancy.

Causes and Risk Factors of Canavan Disease

Canavan disease is a genetic disorder, which means it can only be inherited from the parents. The gene which makes the ASPA enzyme or the aspartoacylase enzyme gets mutated, and Canavan disease occurs. The aspartoacylase enzyme breaks down the NAA or N-Acetyle aspartate, which breaks down a specific brain chemical.

People who are suffering from Canavan disease don't get enough N-Acetyle aspartate or aspartoacylase enzyme buildup in the brain tissue. It damages the white matter of the brain, which is the myelin. Myelin is a fatty substance that forms an insulating layer around nerve fibres, facilitating the efficient transmission of nerve impulses.

As time progresses, the damage to the myelin causes the brain to sustain harm and become more such as a spongy tissue. It also builds up small fluid-filled spaces in that spongy tissue-like brain. This hinders the process of properly sending and receiving signals from the nerves.

Symptoms of Canavan Disease

The infantile Canavan disease has various complicated symptoms which usually occurs between the age of 3 and 6 months, and they are —

- Vision loss
- Muscle spasms
- Difficulty in swallowing or eating
- Hearing loss
- Macrocephaly - abnormally enlarged head and brain (very difficult to control)
- Intellectual disability
- Weak or stiff muscles, atypical muscle tone
- Developmental delays
- Lack of control in motor skills
- Expressing little emotion or interest
- Unresponsive behaviour

Children with infantile Canavan disease become worse very quickly and reach their untimely death by the time they are 10 years old. They have difficulty sitting, walking, eating or crawling, and they lack control of motor skills, which means they have less control over their muscle movements.

People who have the Juvenile type of Canavan disease only suffer mild developmental delays. They may have speech problems and difficulty learning in a typical school environment.

Treatment of Canavan Disease

There is no cure for Canavan disease, but the symptoms can be managed through some treatments. Feeding tubes for proper nutrition and medication to control epileptic episodes, i.e. anticonvulsants and to improve communication and posterity, one can opt for physical therapy. The family can understand the risk of Canavan disease better if they do genetic counselling and genetic testing.

- Physical and Occupational Therapy: These therapies aim to maintain mobility and improve daily functioning.
- Speech and Language Therapy: For individuals with speech and communication difficulties.
- Medications: Symptomatic treatment, including medications to manage seizures or muscle stiffness.
- Assistive Devices: Mobility aids, communication devices, and adaptive equipment to enhance quality of life.
- Respiratory Support: Interventions may be needed to address respiratory issues that can arise in the later stages of the disease.
- Regular Monitoring: Routine assessments to track the progression of the disease and adjust treatment accordingly.

When to Consult a Doctor

Timely medical intervention can help cure many of these ailments or help in managing them. You can also get in touch with the expert Neurology doctors at Narayana Healthcare based in your city to get immediate attention and medical support to treat brain conditions, neurological disorders or any other health concern.

Conclusion

Canavan disease is a neurodegenerative condition which affects the brain and progressively worsens over time. You can consult your healthcare provider for the specific needs and care your child needs if they are suffering from this disease. They can also suggest the family members have DNA testing to prevent Canavan disease in future generations.

Canavan disease is, in most cases, life-threatening, and the symptoms are very severe, but researchers are working on promising treatments.

FAQs

Q. Who is at risk of Canavan Disease? A. Though it might affect anyone but Ashkenazi Jews who have ancestral heritage from Lithuania, Poland and Western Russia are more prone to this disease.

Q. How to prevent Canavan Disease? A. A DNA test determines if both parents carry the genetic mutation. Both parents must be the carriers for the disease to occur in the baby. If one of the parents is not the carrier, then the child will not be born with Canavan disease.

Q. Is there a gene replacement therapy for Canavan Disease? A. rAAV-Olig001-ASPA is a gene therapy that helps prevent damage to myelin. This is myelin's next-generation Canavan gene therapy, which targets Oligodendrocytes. Oligodendrocytes are essential for nerve function and myelin.

Q. How is Canavan Disease treated? A. Therapies such as physical, occupational, speech, and language therapy help treat Canavan Disease.

Reference Links

- https://my.clevelandclinic.org/health/diseases/6013-canavan-disease
- https://myrtellegtx.com/canavan-disease/