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Reviewed July 2014
What is Costeff syndrome?
Costeff syndrome is a condition characterized by vision loss, movement problems, and intellectual disability. People with Costeff syndrome have degeneration (atrophy) of the optic nerves, which carry information from the eyes to the brain. This optic nerve atrophy often begins in infancy or early childhood and results in vision loss that worsens over time. Some affected individuals have rapid and involuntary eye movements (nystagmus) or eyes that do not look in the same direction (strabismus).
Movement problems in people with Costeff syndrome develop in late childhood and include muscle stiffness (spasticity), impaired muscle coordination (ataxia), and involuntary jerking movements (choreiform movements). As a result of these movement difficulties, individuals with Costeff syndrome may require wheelchair assistance.
While some people with Costeff syndrome have intellectual disability that ranges from mild to moderate, many people with this condition have normal intelligence.
Costeff syndrome is associated with increased levels of a substance called 3-methylglutaconic acid in the urine. The amount of the acid does not appear to influence the signs and symptoms of the condition. Costeff syndrome is one of a group of metabolic disorders that can be diagnosed by the presence of increased levels of 3-methylglutaconic acid in urine (3-methylglutaconic aciduria). People with Costeff syndrome also have high urine levels of another acid called 3-methylglutaric acid.
How common is Costeff syndrome?
Costeff syndrome affects an estimated 1 in 10,000 individuals in the Iraqi Jewish population, in which at least 40 cases have been described. Outside this population, only a few affected individuals have been identified.
What genes are related to Costeff syndrome?
Mutations in the OPA3 gene cause Costeff syndrome. The OPA3 gene provides instructions for making a protein whose exact function is unknown. The OPA3 protein is found in structures called mitochondria, which are the energy-producing centers of cells. Researchers speculate that the OPA3 protein is involved in regulating the shape of mitochondria.
OPA3 gene mutations that result in Costeff syndrome lead to a loss of OPA3 protein function. Cells without any functional OPA3 protein have abnormally shaped mitochondria. These cells likely have reduced energy production and die sooner than normal, decreasing energy availability in the body's tissues. It is unclear why the optic nerves and the parts of the brain that control movement are particularly affected.
Read more about the OPA3 gene.
How do people inherit Costeff syndrome?
This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.
Where can I find information about diagnosis or management of Costeff syndrome?
These resources address the diagnosis or management of Costeff syndrome and may include treatment providers.
General information about the diagnosis and management of genetic conditions is available in the Handbook. Read more about genetic testing, particularly the difference between clinical tests and research tests.
To locate a healthcare provider, see How can I find a genetics professional in my area? in the Handbook.
Where can I find additional information about Costeff syndrome?
You may find the following resources about Costeff syndrome helpful. These materials are written for the general public.
You may also be interested in these resources, which are designed for healthcare professionals and researchers.
What other names do people use for Costeff syndrome?
What if I still have specific questions about Costeff syndrome?
Where can I find general information about genetic conditions?
The Handbook provides basic information about genetics in clear language.
These links provide additional genetics resources that may be useful.
What glossary definitions help with understanding Costeff syndrome?
aciduria ; ataxia ; atrophy ; autosomal ; autosomal recessive ; cell ; chorea ; disability ; gene ; inborn errors of metabolism ; inherited ; involuntary ; metabolism ; mitochondria ; newborn screening ; nystagmus ; optic atrophy ; optic nerve ; paraplegia ; population ; protein ; recessive ; screening ; spasticity ; strabismus ; syndrome
You may find definitions for these and many other terms in the Genetics Home Reference Glossary.
See also Understanding Medical Terminology.
References (7 links)
The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? in the Handbook.