Learn more about SLC9A6 (also known as NHE6) and connect with other Simons Searchlight families with the resources below.

Click here for our full SLC9A6 Gene Guide

The online Gene Guide includes more information about SLC9A6 such as the chance of having another child with this condition, behavior and development concerns linked to SLC9A6-related syndrome or specialists to consider for people with this condition. Share this resource with family members or your clinical providers.

What is SLC9A6?

SLC9A6-related syndrome happens when there are changes to the SLC9A6 gene. These changes can keep the gene from working as it should.

The SLC9A6 gene has also been called NHE6. SLC9A6-related syndrome is also called Christianson syndrome.

Key Role

The SLC9A6 gene plays a key role in communication between brain cells.


Because the SLC9A6 gene is important in the development and function of brain cells, many people who have SLC9A6-related syndrome have:

    • Seizures
    • Severe intellectual disability, developmental delay, or both
    • Small head
    • Delayed or absent speech
    • Movement disorders
    • Regression, which may involve losing words or the ability to walk
    • Low muscle tone
    • Autism or features of autism
    • Sleep problems




Do people who have SLC9A6-related syndrome look different?

People who have SLC9A6-related syndrome may look different. Appearance can vary and can include some but not all of these features:

  • Small head
  • Low weight and short height
  • A long, narrow face
  • Thick eyebrows
  • Eyes that look in different directions
  • A mouth held in an open position, with drooling


  • More than one-third of female carriers have attention issues, including attention deficit hyperactivity disorder or ADHD (12/33, or 36 percent).
  • A few receive a psychiatric diagnosis, such as schizoaffective disorder (8/52, or 15 percent).
  • A few have autism (2/20, or 10 percent).


  • About one-third have intellectual disability (19/52, or 37 percent). Among those who do not have an intellectual disability or developmental delay, more than one-third have learning difficulties (6/15, or 40 percent).
  • The majority of female carriers have difficulty processing visual and spatial relationships among objects (8/13, or 62 percent).
  • Some have problems with short and long-term memory (4/13, or 31 percent).


Speech and language are delayed in about one-third of female carriers (6/20, or 30 percent).

Learn more about the SLC9A6 gene and connect with other Simons Searchlight families with the resources below:


Support Resources



GeneReviews are a great resource to bring to your child’s clinicians. These publications provide a summary of current research on genetic conditions and information on ongoing care.

Check out the GeneReviews for Christianson Syndrome.


Research Article Summaries

We currently do not have any article summaries for SLC9A6, but we add resources to our website as they become available.

The information available about SLC9A6 is limited, and families and doctors share a critical need for more information. As we learn more from children who have this gene change, we expect our list of resources and information to grow.

Full versions of published research articles can be found on PubMed. PubMed is a National Institutes of Health (NIH) online database that is free. It has a collection of both medical and scientific research articles. A PubMed search for SLC9A6 articles can be found here.

You can also visit the Simons Foundation’s SFARI Gene website to see information for researchers about this gene.


Research Opportunities

Simons Searchlight

Help the Simons Searchlight team learn more about SLC9A6 genetic changes by taking part in our research. You can learn more about the project and sign up here.

External Research Opportunity: FaceMatch

FaceMatch is a platform that helps parents and doctors contribute to an international secure image database of both undiagnosed and diagnosed children across the globe. *This study is not affiliated with Simons Searchlight. Learn more about FaceMatch.


Family Stories

We do not currently have any stories from SLC9A6 families.

Click here to share your family’s story!