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

SYNGAP1-related non-syndromic intellectual disability



Other Names:
MRD5 ; Syngap1 Gene Mutation Linked To Intellectual Disability, Schizophrenia and Autism ; SYNGAP1-related NSID; MRD5 ; Syngap1 Gene Mutation Linked To Intellectual Disability, Schizophrenia and Autism ; SYNGAP1-related NSID; SYNGAP1 syndrome; Autosomal dominant intellectual disability 5 See More

SYNGAP1-related non-syndromic intellectual disability is a condition that primarily affects the central nervous system. It is characterized by moderate to severe intellectual disability that is usually apparent in the first few years of life. Some affected people may also experience seizures and/or autism spectrum disorder. This condition is caused by changes (mutations) in the SYNGAP1 gene. Almost all reported cases are due to de novo mutations; however, the condition can be passed down to future generations in an autosomal dominant manner. Treatment is based on the signs and symptoms present in each person.[1][2][3]
Last updated: 6/16/2015

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
Learn More:
HPO ID
5%-29% of people have these symptoms
Epileptic encephalopathy 0200134
Microcephaly
Abnormally small skull
Decreased circumference of cranium
Decreased size of skull
Reduced head circumference
Small head circumference
[ more ]
0000252
Torticollis
Wry neck
0000473
1%-4% of people have these symptoms
Seizure 0001250
Percent of people who have these symptoms is not available through HPO
Autistic behavior 0000729
Autosomal dominant inheritance 0000006
Developmental regression
Loss of developmental milestones
Mental deterioration in childhood
[ more ]
0002376
EEG abnormality 0002353
Generalized hypotonia
Decreased muscle tone
Low muscle tone
[ more ]
0001290
Global developmental delay 0001263
Intellectual disability
Mental deficiency
Mental retardation
Mental retardation, nonspecific
Mental-retardation
[ more ]
0001249
Language impairment 0002463
Motor delay 0001270
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Last updated: 7/1/2020

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.

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.

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


Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Patient Registry

  • A registry supports research by collecting of information about patients that share something in common, such as being diagnosed with SYNGAP1-related non-syndromic intellectual disability. The type of data collected can vary from registry to registry and is based on the goals and purpose of that registry. Some registries collect contact information while others collect more detailed medical information. Learn more about registries.

    Registries for SYNGAP1-related non-syndromic intellectual disability:
    SYNGAP1 (MRD5) Patient Registry
    Simons SearchLight
     

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

Social Networking Websites


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 SYNGAP1-related non-syndromic intellectual disability. 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.
  • Unique is a source of information and support for families and individuals affected by rare chromosome disorders. Click on the link to view information about SYNGAP1-related non-syndromic intellectual disability.

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. 
  • PubMed is a searchable database of medical literature and lists journal articles that discuss SYNGAP1-related non-syndromic intellectual disability. 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.


  1. Berryer MH, Hamdan FF, Klitten LL, Møller RS, Carmant L, Schwartzentruber J, Patry L, Dobrzeniecka S, Rochefort D, Neugnot-Cerioli M, Lacaille JC, Niu Z, Eng CM, Yang Y, Palardy S, Belhumeur C, Rouleau GA, Tommerup N, Immken L, Beauchamp MH, Patel GS, Majewski J, Tarnopolsky MA, Scheffzek K, Hjalgrim H, Michaud JL, Di Cristo G. Mutations in SYNGAP1 cause intellectual disability, autism, and a specific form of epilepsy by inducing haploinsufficiency. Hum Mutat. February 2013; 34(2):385-394. http://www.ncbi.nlm.nih.gov/pubmed/23161826.
  2. Hamdan FF, Daoud H, Piton A, Gauthier J, Dobrzeniecka S, Krebs MO, Joober R, Lacaille JC, Nadeau A, Milunsky JM, Wang Z, Carmant L, Mottron L, Beauchamp MH, Rouleau GA, Michaud JL. De novo SYNGAP1 mutations in nonsyndromic intellectual disability and autism. Biol Psychiatry. May 2011; 69(9):898-901. http://www.ncbi.nlm.nih.gov/pubmed/21237447.
  3. Hamdan FF, Gauthier J, Spiegelman D, Noreau A, Yang Y, Pellerin S, Dobrzeniecka S, Côté M, Perreau-Linck E, Carmant L, D'Anjou G, Fombonne E, Addington AM, Rapoport JL, Delisi LE, Krebs MO, Mouaffak F, Joober R, Mottron L, Drapeau P, Marineau C, Lafrenière RG, Lacaille JC, Rouleau GA, Michaud JL; Synapse to Disease Group. Mutations in SYNGAP1 in autosomal nonsyndromic mental retardation. N Engl J Med. Feb 2009; 360(6):599-605. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2925262/.