The children affected at birth usually do not have symptoms but can present some inespecfícicos such as macrocephaly, irritability, difficulty swallowing, retardation, learning disability, drowsiness, hypotonia...
Are apparently healthy, but after a time without treatment, in a situation of infection banal, fever, vaccine, lack of food, anesthesia/surgery, exercise, important, or excess of food, can suffer from an imbalance of your metabolism and present a crisis encefalopática that they lose brain functions, suffer from hypotonia and abnormal movements (dystonias). The impairment can be mild to severe.
Adolescents and adults may present with a late onset of the disease with seizures, altered behavior and movement coordination.