SNP Shot: Genomic Insights

Canavan disease is a rare genetic condition that impairs the communication between nerve cells (neurons) in the brain. It belongs to a category of genetic disorders known as leukodystrophies. These leukodystrophies affect the myelin sheath, the protective covering around nerves, disrupting its growth or upkeep. The myelin sheath is crucial for efficient nerve impulse transmission.

The most prevalent and severe type is neonatal/infantile Canavan disease. Babies with this form may seem typical initially, but developmental issues become apparent around 3 to 5 months of age. They often struggle with motor skills like rolling over, head control, and unsupported sitting. Other common symptoms include weak muscle tone (hypotonia), an abnormally large head (macrocephaly), and irritability. Difficulties with feeding and swallowing, seizures, and sleep problems can also arise.

A less frequent form is the mild/juvenile type of Canavan disease. Individuals with this form experience slight delays in speech and motor skills development, beginning in childhood. These delays can be subtle and general, sometimes going unnoticed as being related to Canavan disease.

The lifespan of individuals with Canavan disease differs depending on the type. Those with the neonatal/infantile form usually survive only into childhood, although some live into adolescence or beyond. Individuals with the mild/juvenile form do not seem to have a reduced life expectancy.

Inheritance:

Canavan disease follows an autosomal recessive inheritance pattern. This means that an individual must inherit a mutated copy of the relevant gene from each parent to develop the condition. The parents, each carrying one copy of the mutated gene, are typically asymptomatic carriers.