The characteristic symptom of<unk>  is the onset of progressively worsening eyesight caused by degeneration of the optic nerve (optic atrophy) within the first few years of childhood, with the majority of affected individuals also developing motor disabilities later in childhood. Occasionally, people with<unk>  may also experience mild cognitive disability. It is type of 3-methylglutaconic aciduria, the hallmark of which is an increased level in the urinary concentrations of 3-methylglutaconic acid and 3-methylglutaric acid; this can allow diagnosis as early as at one year of age. Those with<unk>  typically experience the first symptoms of visual deterioration within the first few years of childhood, which manifests as the onset of progressively decreasing visual acuity. This decrease tends to continue with age, even after childhood. The majority of people with<unk>  develop movement problems and motor disabilities later in childhood, the two most significant of which are choreoathetosis and spasticity. The former causes involuntary erratic, jerky, and twisting movements (see chorea and athetosis), whereas the latter causes twitches and spastic tendencies. These two symptoms are often severe enough to seriously disable an individual; among 36 people with<unk> , 17 experienced major motor disability as a result of choreoathetosis, and 12 experienced spasticity-related symptoms severe enough to do the same. Ataxia (loss of muscle coordination) and speech impairment caused by dysarthria also occur in roughly 50% of cases, but are rarely seriously disabling. Some individuals with<unk>  disease also display mild cognitive impairment, though such cases are relatively infrequent.
Costeff syndrome
Bangstad syndrome
Ross' syndrome
Melnick–Needles syndrome
Feingold syndrome
Young–Simpson syndrome
Raymond–Céstan syndrome
Jeavons syndrome