Canavan disease is a fatal, genetic neurological defect, characterized by progressive cerebral degeneration, especially of the white matter. This condition is one of the leukodystrophies, in which the myelin sheath undergoes degeneration, precipitating neurological defects. The most common form of presentation of the condition is the infantile form, in which affected infants appear quite normal till 3-5 months of age. Symptoms begin to appear after the age of 3-months, and include features such as hypotonia, microcephaly, abnormal posture, feeding difficulties, nasal regurgitation, and head lag. As the infant grows, mental retardation, failure to meet developmental milestones, poor motor skills, seizures, sleep disturbances, and blindness are noticed. Other rare forms of the disease are also noticed, which include the neonatal form, with onset at birth, and the relatively milder juvenile form, appearing after the age of five years.
The disease is frequent among the Ashkenazi Jewish population, where it occurs with an incidence of one affected patient in 6,400 to 13,500 of the population. Other populations which show a high frequency of affected children include those from Eastern Poland, Lithuania, Western Russia, and Saudi Arabia.
Diagnosis of Canavan disease can be done on the basis of increased levels of N-acetylaspartic acid in the urine, blood, or cerebrospinal fluid. In addition, head CT or MRI scans clearly show leukodystrophy. Genetic testing is also available to confirm the diagnosis of Canavan disease. Treatment however, is only of a symptomatic and supportive manner. At present, the prognosis for Canavan disease is poor, with most patients succumbing to the disease before the age of 4-years. Only rarely do children survive unto their teens.