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

Early Infantile Epileptic Encephalopathy 12



Other Names:
Epileptic encephalopathy, early infantile, 12; EIEE12
This disease is grouped under:

Early Infantile Epileptic Encephalopathy type 12 (EIEE12) is an extremely rare nervous system disorder. Infants with EIEE12 develop very frequent epileptic seizures. Seizures present within the first days to months of life. Seizures may trigger eye rolling, eyelid fluttering, lip smacking, drooling, bluish coloring around the mouth, limpness, or muscle stiffening (particularly those in his or her back, legs, and arms).[1][2] The seizures associated with this disease are difficult to treat and the syndrome is severely progressive.[1][3] EIEE12 occurs when a child inherits two mutations in the PLCB1 gene (one from each parent).[3] EIEE12 is inherited in an autosomal recessive fashion. 
Last updated: 7/6/2017

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
Learn More:
HPO ID
Percent of people who have these symptoms is not available through HPO
Autosomal recessive inheritance 0000007
Epileptic encephalopathy 0200134
Focal-onset seizure
Seizure affecting one half of brain
0007359
Generalized-onset seizure 0002197
Hyperreflexia
Increased reflexes
0001347
Hypsarrhythmia 0002521
Muscular hypotonia of the trunk
Low muscle tone in trunk
0008936
Spasticity
Involuntary muscle stiffness, contraction, or spasm
0001257
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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


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

In-Depth Information

  • 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. 

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. NINDS Ohtahara Syndrome Information Page. National Institute of Neurological Disorders and Stroke. June 2015; https://www.ninds.nih.gov/Disorders/All-Disorders/Ohtahara-Syndrome-Information-Page.
  2. Epileptic encephalopathy, early infantile, 12. Online Mendelian Inheritance in Man. Created February 3, 2011; https://www.omim.org/entry/613722. Accessed 7/6/2017.
  3. Early infantile epileptic encephalopathy. Orphanet. July 2014; http://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=EN&Expert=1934.