COMMON QUESTIONS:

As written by Parent Advocates, Liz Marfia-Ash and Phil Ash with contributions from Dr. Stephen Traynelis, Dr. Tim Benke and Melissa Gibbons (Genetic Counselor).

What is GRIN2B?
GRIN2B is not the name of a disease or disorder, but is the name of a gene located on the 12th chromosome. Its function is to encode a protein that forms a receptor responsible for sending chemical messages to the brain. A variation on the GRIN2B gene means that some portion of this specific genetic code either got deleted, duplicated or rearranged. As of 2018, changes to the GRIN2B gene are now being referred to as GRIN2B-Related Neurodevelopmental Disorder.

What causes variations on the GRIN2B gene?
A GRIN2B variation occurs randomly and spontaneously at or shortly after conception. The reasons for these genetic changes are unknown. It is possible for a parent to be a carrier of the change and pass it on to their children, but most known cases are found to be de novo (meaning, it occurs spontaneously in the DNA of the egg or sperm that formed the new child).

Who can receive a GRIN2B diagnosis?
Males and females of all races can be born with a GRIN2B variation. So far, we know of over five hundred individuals diagnosed from 50+ countries all over the world.

I’m confused by the terms. What is the difference between a variation and a mutation?
Anytime a change is made to a gene, it can be referred to as a change, variation, mutation or sometimes chromosomal rearrangement. These terms have often been used interchangeably, though “mutation” is being used less often due to its negative connotation.

What are the Symptoms?
Symptoms can vary from person to person depending on the type and location of the variation, but the most common traits (as reported by parents in the GRIN2B parent support group) are hypotonia (low muscle tone), gross and fine motor disabilities, intellectual disability and non-verbal or limited speech. For a detailed list of additional symptoms, please check out our Symptoms infographic on About GRIN2B.

Is there a cure?
At this time, there is no cure for a GRIN2B change because it occurs at the genetic level of an individual. It is also important to understand how new and barely understood this diagnosis is. Though some Researchers have been studying this gene for decades, there has been no clinical understanding of this diagnosis. GRIN2B Foundation was the first patient advocacy group formed to support this rare disorder. As other GRIN2B and GRIN-gene patient groups are forming internationally, we are collaborating with them and with medical professionals around the world to fund research. One day, this research will lead to better care and treatments for all those with GRIN2B-Related Neurodevelopmental Disorder.

What are the treatments?
While there is presently no cure for a GRIN2B change, physical, occupational, and speech therapies can help manage symptoms in children and may help them reach developmental milestones in their own time. Epilepsy, if present, is treated by a specialist. There are no FDA-approved medications on the market to specifically alleviate the symptoms associated with GRIN2B. However, there are a number of experimental medicines and homeopathic treatments that have been shown to have some success as reported by some parents in the GRIN2B parent support group. For more information, check out our Clinical Trials page.

What kind of equipment might my child with GRIN2B-Related Neurodevelopmental Disorder need?
Parents have reported needing a variety of equipment depending on their child’s specific symptoms, including, but not limited to orthotics (afo’s and smo’s), wheelchairs, standers, walkers, specialty car seats, bath seats and safety beds. For children with more limited speech, some families have found success using Augmentative and Alternative Communication device (AAC). Additionally, many children report having extreme sensory sensitivities and may receive some benefits from the use of compression garments, chewy tubes, swings, weighted blankets. Please consult your child’s medical professional and do your own careful research before purchasing any of these items.

How is a GRIN2B variation diagnosed?
GRIN2B changes are not diagnosed easily. Often GRIN2B children will have normal MRIs, normal EEGs and normal chromosome pairings – common tests that can often help diagnose other, more common genetic disorders. In most instances, GRIN2B variations are discovered through a genetic blood test called Whole Exome Sequencing (WES). This blood test examines the individual’s entire genetic makeup. This is compared with the genetic sequences of the parents. Through this test, rare genetic outliers like GRIN2B changes can be determined and diagnosed. This test has only really become more widely available and covered by insurance in the past few years, which explains why there are so few known individuals. As this test becomes more prevalent, we expect the number of individuals diagnosed with a GRIN2B change to grow. Additional tests that may detect a GRIN2B diagnosis are a Microarray or Autism and Epilepsy Panels.

What is the prognosis?
To date, we know of only a few deaths that have occurred in individuals due to complications with the GRIN2B diagnosis. This disorder does not appear to be progressive, meaning it does not worsen over time. But keep in mind, there is likely a larger population out there with undiagnosed GRIN2B changes, so the phenotype and prognosis will continue to evolve.

What can I do to help?
Consider making a donation to our organization. Your donations will help us further our mission. We know so little about GRIN2B and we have a long road ahead of us in terms of funding research. Please follow our Facebook, Twitter and Instagram pages for updates on additional ways to help. If you are interested in being a volunteer, we are specifically looking for people to help us plan our Family Weekend in July 2024. We are also always in need of volunteers who have skills in the following areas: Legal, Marketing, Social Media Management, Event planning, Finance and anyone with a medical or scientific background. Email liz.marfia-ash@grin2b.com if you have any of the previously-mentioned skills and are interested in sharing your expertise.

If you are a Parent, please register your child for as many studies as possible. In order for us to better understand a GRIN2B diagnosis and someday develop treatments, we need to have as much patient data as possible. There are several current studies collecting data under our Research tab. If you haven’t already done so, please sign up for our Contact Registry so we can keep you informed on new research studies and relevant events.

Download our GRIN2B Registries Infographic.