Three different forms of Canavan disease (CD)
have been described (neonatal, infantile, and late-onset form). The
infantile form seems to be the most common form, and only the rate of disease
progression is highly variable. Onset is usually in early infancy at 2
to 4 months of age with loss of the already acquired milestones, while death
occurs most often within the first decade of life (although death by
approximately 18 months of age is not uncommon). However, survival into the
teens has also been reported, and one patient survived for more than 30 years.
Patients initially present with poor head control due to hypotonia or atonia
of the neck muscles. Hypotonia soon becomes generalized and changes to
spastic diplegia or quadriplegia as the disease progresses, ending in late
decerebrate or decorticate posturing. Generalized seizures are common.
Ocular features include optic atrophy, nystagmus, and finally blindness.
Closure of the anterior fontanelle is delayed, and macrocephaly is a common
finding. Patients usually are deaf. Copious oral secretions and
gastroesophageal reflux can occur. No effective treatment is available.
Therapies are mainly symptomatic (e.g., seizure control, physiotherapy).
Gene therapies are currently under investigation.