Costeff syndrome

Costeff syndrome, or 3-methylglutaconic aciduria type III, is a genetic disorder caused by mutations in the OPA3 gene. It is typically associated with the onset of visual deterioration (optic atrophy) in early childhood followed by the development of movement problems and motor disability in later childhood, occasionally along with mild cases of cognitive deficiency. The disorder is named after Hanan Costeff, the doctor who first described the syndrome in 1989. Costeff syndrome, or 3-methylglutaconic aciduria type III, is a genetic disorder caused by mutations in the OPA3 gene. It is typically associated with the onset of visual deterioration (optic atrophy) in early childhood followed by the development of movement problems and motor disability in later childhood, occasionally along with mild cases of cognitive deficiency. The disorder is named after Hanan Costeff, the doctor who first described the syndrome in 1989. The characteristic symptom of Costeff syndrome 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 Costeff syndrome 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 Costeff syndrome 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 Costeff syndrome 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 Costeff syndrome, 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 Costeff disease also display mild cognitive impairment, though such cases are relatively infrequent. Costeff syndrome is a neuro-ophthalmological genetic disorder; specifically, it is an autosomal recessive disorder caused by a mutation in the OPA3 gene, which carries instructions for synthesis of its gene product, the OPA3 protein. The exact function of the product protein is unknown, though it is known to play an integral role in mitochondrial function. The disorder can be caused by several different mutations in the OPA3 gene. However, nearly all reported cases of Costeff syndrome has been in individuals of Iraqi Jewish origin, all of whom share the same splice site founder mutation.