Below is a summary for the KMT2C gene observed in research publications. This is not meant to take the place of medical advice.

What is Kleefstra syndrome 2?

Kleefstra syndrome 2 happens when there are changes to the KMT2C. These changes can keep the gene from working as it should.

Key Role

The KMT2C gene plays an important role in human development.


Because the KMT2C gene is important for the proper function of the body’s cells, some people may have:

  • Short height
  • Poor growth
  • Sideways curvature of the spine, also called scoliosis
  • Delayed motor development
  • Intellectual disability
  • Speech delay
  • Seizures
  • Autism

Do people who have Kleefstra syndrome 2 look different?

People with Kleefstra syndrome 2 may look different. Appearance can vary and can include, but are not limited to, these features:

  • Lower than average muscle tone
  • Smaller than average head size
  • Flatter than average middle of the face
  • Eyebrows that stand out

How many people have Kleefstra syndrome 2?

As of 2023, about 12 people with Kleefstra syndrome 2 have been described in medical research.


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.

There is currently no GeneReviews for KMT2C.


Research Article Summaries

Below, we have summarized research articles about changes in the KMT2C gene. We hope you find this information helpful.

The information available about KMT2C is limited, and families and doctors share a critical need for more information. As we learn more from children who have a change in this gene, we expect this 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 KMT2C articles can be found here.

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


Synaptic, transcriptional and chromatin genes disrupted in autism

Original research article by S. De Rubeis et al. (2014).

Read the abstract here and the Simons Searchlight summary here.


Research Opportunities

Simons Searchlight

Help the Simons Searchlight team learn more about KMT2C genetic changes by taking part in our research. You can learn more about the project and sign up here.


Family Stories

Stories from KMT2C families:

Click here to share your family’s story!