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Disease Profile
OPA3 defect
Prevalence
Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.
Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.
Unknown
Age of onset
Childhood
ICD-10
E71.1
Inheritance
Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.
Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.
X-linked
dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.
dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.
X-linked
recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.
recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.
Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.
Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.
Not applicable
Other names (AKA)
MGA3; 3-alpha methylglutaconic aciduria type III; MGA type III;
Categories
Congenital and Genetic Diseases; Eye diseases; Metabolic disorders;
Summary
The following summary is from Orphanet, a European reference portal for information on rare diseases and orphan drugs.
Orpha Number: 67047
Definition
3-methylglutaconic aciduria type III (MGA III) is an organic aciduria characterised by the association of optic atrophy and choreoathetosis with 3-methylglutaconic aciduria.
Epidemiology
The vast majority of reported cases involved the Iraqi-Jewish population, in which the prevalence of the disorder has been estimated at around 1 in 10 000.
Onset of the optic atrophy occurs during infancy with a progressive decrease in visual acuity. The choreoathetoid movement disorder manifests later, usually within the first ten years of life. Other clinical features may include spastic paraparesis, mild ataxia and cognitive deficit, dysarthria , and nystagmus .
MGA III is caused by mutations in the OPA3 gene (19q13.2-q13.3). The biological function of the OPA3 gene product remains to be defined but MGA III is hypothesised to be a primary mitochondrial disorder .
Diagnosis may be suspected up on presentation with early-onset optic atrophy and choreoathetosis (particularly in individuals of Iraqi-Jewish origin) and by detection of an elevation in the levels of 3-methylglutaconic and 3-methylglutaric acid in the urine. Diagnosis can be confirmed by detection of mutations in the OPA3 gene.
MGA type III can be distinguished from other forms of MGA (types I, II and IV; see these terms) on the basis of the clinical phenotype and, more specifically, from 3-MGA type I by the absence of an elevation in 3-hydroxyisovaleric acid levels and normal 3-methylglutaconyl-CoA hydratase activity in cultured fibroblasts . The differential diagnosis may also include Behr syndrome (see this term) and cerebral palsy.
Prenatal testing is clinically available for affected families through molecular analysis of amniocytes or chorionic villus samples.
MGA III is transmitted as an autosomal recessive trait .
Management and treatment
Treatment is symptomatic only and should be managed by a multidisciplinary team.
The long-term prognosis remains unknown: although the disease progresses during childhood, it appears to stabilise during early adulthood.
Visit the Orphanet disease page for more resources.
Symptoms
This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.
| Medical Terms | Other Names |
Learn More:
HPO ID
|
|---|---|---|
| 80%-99% of people have these symptoms | ||
| 3-Methylglutaconic aciduria | 0003535 | |
| Choreoathetosis | 0001266 | |
| Visual impairment |
Impaired vision
Loss of eyesight
Poor vision
[ more ] |
0000505 |
| 30%-79% of people have these symptoms | ||
| 0001251 | ||
|
Difficulty articulating speech
|
0001260 | |
|
Mental deficiency
Mental retardation
Mental retardation, nonspecific
Mental-retardation
[ more ] |
0001249 | |
|
Involuntary, rapid, rhythmic eye movements
|
0000639 | |
| Spastic paraparesis | 0002313 | |
| 5%-29% of people have these symptoms | ||
| Gait disturbance |
Abnormal gait
Abnormal walk
Impaired gait
[ more ] |
0001288 |
| 1%-4% of people have these symptoms | ||
| 3-Methylglutaric aciduria | 0003344 | |
| Optic atrophy | 0000648 | |
| Percent of people who have these symptoms is not available through HPO | ||
| Abnormality of extrapyramidal motor function | 0002071 | |
| 0000007 | ||
| Babinski sign | 0003487 | |
| Chorea | 0002072 | |
| Cognitive impairment |
Abnormality of cognition
Cognitive abnormality
Cognitive defects
Cognitive deficits
Intellectual impairment
Mental impairment
[ more ] |
0100543 |
| Hyperreflexia |
Increased reflexes
|
0001347 |
| Reduced visual acuity |
Decreased clarity of vision
|
0007663 |
|
Involuntary muscle stiffness, contraction, or spasm
|
0001257 | |
Diagnosis
Making a diagnosis for a genetic or rare disease can often be challenging. Healthcare professionals typically look at a person’s medical history, symptoms, physical exam, and laboratory test results in order to make a diagnosis. The following resources provide information relating to diagnosis and testing for this condition. If you have questions about getting a diagnosis, you should contact a healthcare professional.
Newborn Screening
- An ACTion (ACT) sheet is available for this condition that describes the short-term actions a health professional should follow when an infant has a positive
newborn screening result. ACT sheets were developed by experts in collaboration with the American College of Medical Genetics. - An Algorithm flowchart is available for this condition for determining the final diagnosis in an infant with a positive newborn
screening result. Algorithms are developed by experts in collaboration with the American College of Medical Genetics. - Baby's First Test is the nation's newborn screening education center for families and providers. This site provides information and resources about screening at the local, state, and national levels and serves as the Clearinghouse for newborn screening information.
- National Newborn Screening and Global Resource Center (NNSGRC) provides information and resources in the area of newborn screening and genetics to benefit health professionals, the public health community, consumers and government officials.
Organizations
Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.
Organizations Supporting this Disease
-
Organic Acidemia Association
9040 Duluth Street
Golden Valley, MN 55427
Telephone: 763-559-1797
Fax: 866-539-4060
E-mail: mkstagni@gmail.com
Website: https://www.oaanews.org/
Learn more
These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.
Where to Start
- Genetics Home Reference (GHR) contains information on OPA3 defect. This website is maintained by the National Library of Medicine.
In-Depth Information
- GeneReviews provides current, expert-authored, peer-reviewed, full-text articles describing the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.
- The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
- Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine.
- Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
- PubMed is a searchable database of medical literature and lists journal articles that discuss OPA3 defect. Click on the link to view a sample search on this topic.