This is one of many hereditary congenital disorders of brain degeneration (encephalopathy) resulting from gene mutations. It is a rare condition and only a few families have been reported.
This is an early onset and progressive neurodegenerative disorder that may have signs such as weak muscles (hypotonia) at birth. Lack of normal neurological development becomes evident in the first year of life. Infants do not achieve the usual early childhood milestones such as sitting, walking and speech. There is considerable variation in the clinical progression and some infants that may develop early speech that often have a slurred quality to it. The degree of cognitive impairment varies widely but is often severe, accompanied by balance difficulties (ataxia), and stiff muscles in the limbs. Muscles may show wasting as well.
Brain imaging reveals evidence of degenerative changes and muscle biopsy shows lack of normal nerve pathways. The optic nerve that transmits visual symptoms is usually pale revealing lack of normal functioning.
This condition is caused by mutations in a specific gene. Both members of that gene are changed in patients while the parents, who carry only one mutation, are clinically normal but the offspring of two such parents inherit a 25% risk of getting this condition.
Newborns may have neurological signs of brain disease that suggest widespread developmental damage. Neurologists, pediatricians and ophthalmologists may collaborate on the diagnosis and care. In mild cases the signs of developmental delays may not be apparent for several months but progression of the brain damage soon make the widespread disease apparent. MRIs of the brain reveals more signs of the brain disease. Vision is subnormal but the cognitive impairment prevents quantitation.
No treatment has been reported. Many individuals require full time supportive care. The impact on longevity has not been reported.