National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Glutaric acidemia type I


Other Names:
Glutaric acidemia type 1; Glutaric acidemia 1; Glutaric aciduria 1; Glutaric acidemia type 1; Glutaric acidemia 1; Glutaric aciduria 1; GA 1; Glutaryl-CoA dehydrogenase deficiency See More
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Glutaric acidemia type I (GA1) is a genetic metabolic disorder. People with GA1 don't make enough of one of the enzymes needed to break down certain amino acids found in the proteins we eat. Without enough of the enzyme, the breakdown products of these amino acids build up in tissues of the body. The buildup of these chemicals can damage the brain, especially the area of the brain called the basal ganglia. The basal ganglia helps control the body's movements.[1][2] 

Without treatment, newborns with GA1 may at first not have any symptoms other than possibly having a slightly large head. Some, however, may have weak muscles and early signs of developmental delay. For most children with GA1, if untreated, an infection or fever will trigger an episode that causes serious damage to the basal ganglia. In some children, the brain damage will happen without a triggering fever. Damage to the basal ganglia will make it hard for the child to control the movements of their body. The damage cannot be reversed. However if treatment is started in a newborn with GA1 before symptoms begin, 80-90% of people with GA1 will not develop symptoms. Treatment however must be followed strictly, especially for the first six years of life. Treatment includes a low-lysine diet, carnitine supplementaion, and emergency treatment during an fever or acute episode.[1][2]

GA1 is caused by mutations in the GCDH gene and is inherited in an autosomal recessive manner. GA1 is included on the newborn screening panel in most countries.[1][2] 
Last updated: 4/18/2017
If treatment is started as a newborn before symptoms begin, 80-90% of people with glutaric acidemia type 1 (GA1) will not develop any symptoms. However, if treatment is not started early or is not followed properly, the severity of symptoms varies from person to person. Symptoms usually begin in infancy or early childhood, but sometimes symptoms begin in adolescence or adulthood. In rare cases, a person with GA1 does not develop any symptoms, even if not treated.[1][2] 

Many newborns with GA1 have a large head circumference (macrocephaly), but may not have any other symptom. About half will have weak muscle tone (hypotonia) and early signs of developmental delay. If GA1 is untreated, an infection or fever will usually trigger an acute episode that causes serious damage to the basal ganglia. The basal ganglia is the area of the brain that helps control movement. In some children, the brain damage will happen without a triggering fever. Damage to the basal ganglia, especially before the age of 6 years old, can cause a complex movement disorder, similar to cerebral palsy. Controlling the movement of hands, arms, feet, legs, head, and neck may become very hard. Movements may be jerky or rigid. Muscle spasms may occur. Repeated stress on the body (such as infection and fever) can cause symptoms to worsen. Some studies have shown that the intellectual ability of a person with GA1, even if untreated, is not affected. Others report that although not common, mild to moderate intellectual disabilities may occur in some untreated children.[1][2]
Last updated: 4/18/2017

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.

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Medical Terms Other Names
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HPO ID
80%-99% of people have these symptoms
Dyskinesia
Disorder of involuntary muscle movements
0100660
Dystonia 0001332
Encephalopathy 0001298
Large fontanelles
Wide fontanelles
0000239
Metabolic acidosis 0001942
Vomiting
Throwing up
0002013
30%-79% of people have these symptoms
Abnormal facial shape
Unusual facial appearance
0001999
Abnormality of extrapyramidal motor function 0002071
Choreoathetosis 0001266
Feeding difficulties in infancy 0008872
Irritability
Irritable
0000737
Joint dislocation
Joint dislocations
Recurrent joint dislocations
[ more ] 		0001373
Macrocephaly
Increased size of skull
Large head
Large head circumference
[ more ] 		0000256
Muscular hypotonia
Low or weak muscle tone
0001252
Prominent forehead
Pronounced forehead
Protruding forehead
[ more ] 		0011220
Spasticity
Involuntary muscle stiffness, contraction, or spasm
0001257
5%-29% of people have these symptoms
Abnormal retinal vascular morphology
Abnormality of retina blood vessels
0008046
Abnormality of eye movement
Abnormal eye movement
Abnormal eye movements
Eye movement abnormalities
Eye movement issue
[ more ] 		0000496
Cerebral ischemia
Disruption of blood oxygen supply to brain
0002637
Cognitive impairment
Abnormality of cognition
Cognitive abnormality
Cognitive defects
Cognitive deficits
Intellectual impairment
Mental impairment
[ more ] 		0100543
Coma 0001259
Developmental regression
Loss of developmental milestones
Mental deterioration in childhood
[ more ] 		0002376
Gait disturbance
Abnormal gait
Abnormal walk
Impaired gait
[ more ] 		0001288
Hemiplegia
Paralysis on one side of body
0002301
Intracranial hemorrhage
Bleeding within the skull
0002170
Malignant hyperthermia 0002047
Migraine
Intermittent migraine headaches
Migraine headache
Migraine headaches
[ more ] 		0002076
Neurological speech impairment
Speech disorder
Speech impairment
Speech impediment
[ more ] 		0002167
Seizure 0001250
Vertigo
Dizzy spell
0002321
Percent of people who have these symptoms is not available through HPO
Autosomal recessive inheritance 0000007
Delayed myelination 0012448
Dilation of lateral ventricles 0006956
Failure to thrive
Faltering weight
Weight faltering
[ more ] 		0001508
Generalized hypotonia
Decreased muscle tone
Low muscle tone
[ more ] 		0001290
Glutaric acidemia 0003530
Glutaric aciduria 0003150
Hepatomegaly
Enlarged liver
0002240
Hyperketonemia
Increased level of ketone bodies in blood
0410175
Hypoglycemia
Low blood sugar
0001943
Infantile encephalopathy 0007105
Ketonuria 0002919
Opisthotonus 0002179
Rigidity
Muscle rigidity
0002063
Spastic diplegia 0001264
Symmetrical progressive peripheral demyelination 0006873
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Last updated: 7/1/2020
Glutaric acidemia type I (GA1) can be passed down in families. This is because GA1 is caused by changes or mutations in the GCDH gene.[1] Like most genes, the GCDH gene comes in a pair (two copies). One copy comes from the mother and one copy from the father. In order to have GA1, both copies of the GCDH gene must have a mutation. This means that GA1 is an autosomal recessive disorder.[3] A person with a mutation in only one copy of the GCDH gene is called a carrier. Carriers of an autosomal recessive disease like GA1 usually have no signs or symptoms.

When 2 carriers of GA1 have children, each child has a:
  • 25% chance of having GA1
  • 50% chance to be a carrier of GA1 like each parent
  • 25% chance of not having GA1 and not being a carrier of GA1 (in other words, having two normal copies of the gene)
If a person with GA1 and a carrier of GA1 have children, each child has a:
  • 50% chance of having GA1
  • 50% chance of being a carrier
If a person with GA1 and a person who has two normal copies of the GCDH gene have children, each child will be a carrier of GA1.
Last updated: 4/18/2017
The Genetic Testing Registry (GTR) provides information about the labs that offer genetic testing for this condition. The intended audience for the GTR is health care providers and researchers. Therefore, patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.
Last updated: 4/29/2015

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.
  • The Newborn Screening Coding and Terminology Guide has information on the standard codes used for newborn screening tests. Using these standards helps compare data across different laboratories. This resource was created by the National Library of Medicine.
  • 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.

The resources below provide information about treatment options for this condition. If you have questions about which treatment is right for you, talk to your healthcare professional.

Management Guidelines

  • Orphanet Emergency Guidelines is an article which is expert-authored and peer-reviewed that is intended to guide health care professionals in emergency situations involving this condition.  
Glutaric acidemia type 1 (GA1) is a treatable disorder. If treatment begins in the newborn period before symptoms begin, and the treatment is followed properly, children with GA1 usually grow and develop normally. However, since newborn screening for GA1 (allowing treatment to begin before symptoms) only began in the 1990s, it is not yet known if GA1 may cause complications later in life.[1][2]

If not promptly and properly treated, GA1 usually causes serious, irreversible, neurologic damage. The damage mainly affects control of voluntary muscle movement. The overall impact of GA1 on a person's life will depend on the amount of damage to the brain, but can be severe. In general, a person with GA1 who has an acute brain damaging episode before the age of 6 years old is at increased risk for medical problems throughout their life, and their life expectancy is shortened.[1][2] 
Last updated: 4/18/2017

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources

Related diseases are conditions that have similar signs and symptoms. A health care provider may consider these conditions in the table below when making a diagnosis. Please note that the table may not include all the possible conditions related to this disease.

Conditions with similar signs and symptoms from Orphanet
GDD is often misdiagnosed. Differential diagnosis includes encephalitis, Reye's syndrome, familial infantile bilateral striatal necrosis, familial megalencephaly, postencephalitic Parkinsonism (see these terms), dystonic cerebral palsy, battered child syndrome with chronic subdural effusions, sudden infant death syndrome and vaccine induced brain-injury.
Visit the Orphanet disease page for more information.

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

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 Glutaric acidemia type I. This website is maintained by the National Library of Medicine.
  • The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.
  • The Screening, Technology And Research in Genetics (STAR-G) Project has a fact sheet on this condition, which was written specifically for families that have received a diagnosis as a result of newborn screening. This fact sheet provides general information about the condition and answers questions that are of particular concern to parents.

In-Depth Information

  • 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 Glutaric acidemia type I. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know. Submit a new question

  • My husband is a carrier of glutamic acidemia type I. I am not a carrier. Are our children at risk to develop this condition? Are all individuals with glutaric acidemia identified in infancy? Where can I access genetic testing for glutaminc acidemia type I? See answer


  1. Boy N, Mühlhausen C, Maier EM, et al. Proposed recommendations for diagnosing and managing individuals with glutaric aciduria type I: second revision. J Inherit Metab Dis. January 2017; 40(1):75-101. https://www.ncbi.nlm.nih.gov/pubmed/27853989.
  2. Mosaeilhy A, Mohamed MM, C GP, El Abd HS, Gamal R, Zaki OK, Zayed H. Genotype-phenotype correlation in 18 Egyptian patients with glutaric acidemia type I. Metab Brain Dis. April 7 2017; [Epub ahead of print]:https://www.ncbi.nlm.nih.gov/pubmed/28389991.
  3. Glutaric acidemia type I. Genetics Home Reference (GHR). March, 2007; http://www.ghr.nlm.nih.gov/condition/glutaric-acidemia-type-i.