Infantile Neuroaxonal Dystrophy (INAD) is a rare, progressive, and inherited degenerative disorder that primarily affects the central nervous system (CNS) in infants and young children. Also known as Seitelberger disease, it is characterized by the abnormal accumulation of neuroaxonal spheroids, which are abnormal swellings in nerve fibers, throughout the brain and spinal cord.
INAD typically presents in early childhood, between 6 months and 2 years of age, and manifests with a wide range of symptoms. These may include delays in reaching developmental milestones, progressive loss of previously acquired skills, muscle weakness, muscle stiffness (spasticity), poor coordination, speech impairments, and visual problems. As the disease progresses, affected individuals may also experience seizures, intellectual disability, and eventually become wheelchair-bound.
The underlying cause of INAD is a mutation in the PLA2G6 gene, which is responsible for encoding an enzyme crucial for the breakdown of fats within nerve cells. The impaired function of this enzyme leads to the abnormal buildup of lipid-containing structures called spheroids, resulting in the progressive destruction of nerve cells.
Unfortunately, there is currently no cure for INAD. Treatment mainly focuses on managing symptoms and providing supportive care to improve quality of life. This may involve physical therapy, speech therapy, occupational therapy, and medication to control seizures and muscle stiffness.
The prognosis for individuals with INAD is generally poor, with most affected children experiencing a rapid decline in neurological function and a shortened lifespan, typically by early adulthood.
