SYNGAP1-related disorder is a genetic developmental condition caused by genetic changes in the SYNGAP1 gene. It is characterised by developmental delay, epilepsy, seizures, intellectual disability and autism spectrum disorder.

Below on this page is some information about this condition as well as links to useful resources for Australians living with a rare disease.

Synonyms: SYNGAP-1 related developmental and epileptic encephalopathy, SYNGAP-1 DEE, SYNGAP1 syndrome, SYNGAP1-related intellectual disability, SYNGAP1-ID.

Universal rare disease classifications provide a common language for recording, reporting and monitoring diseases. Please visit the Rare Disease Classifications page for more information about these internationally recognised classifications.

ORPHA:544254 SYNGAP1-related developmental and epileptic encephalopathy

ICD-11: LD90.Y Other specified conditions with disorders of intellectual development as a relevant clinical feature

Rare diseases typically display a high level of symptom complexity. There is often a wide range of symptoms and the symptoms may vary between individuals in terms of its presentation, severity, duration and impact.

Please speak to your medical team to learn more about the symptoms of this condition.

Rare diseases are often serious and progressive, exhibiting a high degree of symptom complexity, leading to significant disability. Majority of the estimated two million Australians living with a rare disease meet the Australian Government’s definition for disability (in accordance to the Australian Public Service Commission and Australian Bureau of Statistics), and many experience severe and permanent disability impacts. If you or someone you care for is experiencing disability-related impacts from a rare condition, please speak with a health or disability professional for advice. Information about relevant disability support can be found at the RARE Portal’s Disability Support Information page.

SYNGAP1-related disorder is a genetic condition caused by disease-causing genetic changes (variants) in the Synaptic Ras-GTPase-activating protein 1/SYNGAP1 gene on chromosome 6, which is crucial for neuron development and function.

Everyone has two copies of the SYNGAP1 gene, one from each parent. SYNGAP1-related disorder is an autosomal dominant condition, which means that having a genetic variant in just one of the SYNGAP1 gene copies can result in the condition. More information on autosomal dominant inheritance pattern can be found at Centre for Genetics Education: Autosomal dominant inheritance.

For most individuals with SYNGAP1-related disorder, their genetic variant in SYNGAP1 gene occurs randomly (de novo) prior to birth. In rare cases, the autosomal dominant genetic variant was inherited from an affected parent with mild symptoms.

If you would like to learn more about the inheritance and impact of this condition, please ask your doctor for a referral to a genetic counsellor. Genetic counsellors are qualified allied health professionals who can provide information and support regarding genetic conditions and testing. More information about genetic counselling can be found at:

• Information on Genetic Services
• The National and State Services pages underneath the ‘Genetic Counselling’ sections listed

A timely diagnosis is critical for better patient outcomes, the provision of the best possible care and treatment options, access to services and support, increased reproductive confidence and the ability to participate in clinical trials.

Please speak to your medical team to learn more about the available diagnostic pathways for this condition.

Please speak to your medical team to learn more about the possible treatment or management options for your condition. Treatment will depend on an individual’s specific condition and symptoms. It is also important to stay connected to your medical team so that you can be made aware of any upcoming clinical trial opportunities.

Clinical care for rare diseases often involves a multidisciplinary team of medical, care and support professionals. Please note that the information provided here is as a guide and that RVA does not necessarily monitor or endorse specific clinics or health experts.

Healthcare professionals involved in the treatment of SYNGAP1-related disorder may include general practitioners (GP), paediatricians, neurologists, psychologists, gastroenterologists, urologists, orthopaedic specialists, physical therapists, occupational therapists, speech pathologists, and dietitians. The need for different healthcare professionals may change over a person’s lifetime and extend beyond those listed here.

If you know of any relevant care guidelines, please let us know via the Contribute page.

Individuals living with rare diseases may have complex medical issues and disabilities, which are not always visible. It is often useful to refer to their medical history as well as personal information such as a medical card, doctor’s letter, or if available, a rare disease passport, for relevant information.

If you know of any relevant emergency management guidelines or information relevant to emergency care, please let us know via the Contribute page.

There are specific considerations around participating in rare disease research, including clinical trials. It is important to be mindful of issues such as data privacy, research ethics, consent and differences in research regulations between Australia and other countries.

If you are interested in finding clinical trials for your condition, please visit the following websites; however, there may not be any clinical trials available:

• Australian Clinical Trials
• ClinicalTrials.gov

It is best to discuss your interest in any clinical trials with your medical team to determine suitability and eligibility.

Please note that RVA does not necessarily monitor or endorse each group/organisation’s operational governance and activities.

Australian Organisation:
Syngap Research Fund Australia
Website: https://www.syngapaustralia.org/

Global Organisation:
SYNGAP Research Fund
Website: https://curesyngap1.org/

Please note that RVA does not monitor or endorse each group/organisation’s operational governance and activities. When engaging with a group, please consider the information on the RARE Portal’s Finding Helpful Peer and Community Supports page.

SYNGAP1-related disorder varies between individuals, and each person’s experience is unique.

Syngap Research Fund: Our Stories has personal stories of people living with SYNGAP1-related disorder.

If you would like to share your personal story with RVA, please visit the Rare Voices Australia: Share Your Story page. RVA will consider your story for publishing on our website and inclusion on the RARE Portal.

For information on available government and social services that provide support for individuals with a rare disease, please visit the National and State Services pages.

People living with a rare disease, including families and carers, often face unique challenges such as diagnostic delays, misdiagnoses, limited treatment options, and limited access to rare disease specialists and support. These challenges may impact people’s emotional wellbeing and quality of life. Many people find it helpful to seek mental health and wellbeing support to cope with ongoing stress and uncertainty. Connecting with people who have shared experiences through a support group may also be helpful. Information about relevant mental health and wellbeing support can be found at:

• Mental Health and Wellbeing Support for Australians Living with a Rare Disease
• The National and State Services pages underneath the ‘Mental Health’ sections listed

Further information on SYNGAP1-related disorder can be found at:

• Genetic and Rare Diseases (GARD) Information Center: SYNGAP1-related developmental and epileptic encephalopathy
• National Organization for Rare Disorders (NORD): SYNGAP1-related NSID

SynGAP Research Fund: Medical Care Considerations for SYNGAP1 Encephalopathy

GeneReviews®: SYNGAP1-Related Intellectual Disability

Online Mendelian Inheritance in Man, OMIM®: #612621 Intellectual developmental disorder, autosomal dominant 5; MRD5

Orphanet: SYNGAP1-related developmental and epileptic encephalopathy

Human Phenotype Ontology (HPO): SYNGAP1-related developmental and epileptic encephalopathy

This page has been developed by Rare Voices Australia (RVA)’s RARE Portal team. If you would like to see more information added to this page, please reach out via the Contact form. If you would like to share relevant resources for this condition, please visit the Contribute page.

If you are aware of any additional information that may benefit stakeholders with an interest in this page, or if you notice any broken links or inaccurate information, please let us know via the Contribute page.