What Is KMT2B-Related Dystonia?
KMT2B-related dystonia is a rare neurological disorder caused by mutations in the KMT2B gene, a gene located on chromosome 19 involved in regulating other genes crucial for brain development. First discovered in 2016, this disorder is also called DYT-KMT2B or Dystonia-28.
The KMT2B mutation leads to movement disorders, typically starting in childhood, and often progresses from limb dystonia to affect the face, neck, and voice. Because of its rarity and the variety of symptoms, it’s frequently misdiagnosed—or not diagnosed at all for years.
How Rare Is KMT2B?
As of today, researchers have identified:
- 246 people with dystonia caused by KMT2B mutations across 229 families
- 27 additional individuals with non-dystonic neurodevelopmental forms of KMT2B
That places the number of known global cases under 300 total, and in many countries, fewer than 100 individuals are documented.
Symptoms and Progression
KMT2B-related dystonia typically starts around age 6 and gradually spreads over 4–5 years. Common features include:
- Limb dystonia (arms/legs twist or stiffen involuntarily)
- Facial and voice muscle involvement
- Developmental delays
- Intellectual disability
- Psychiatric symptoms (ADHD, anxiety, OCD)
- Hearing loss
- Dysmorphic facial features
It can look different from person to person and often overlaps with more familiar disorders, which adds to diagnostic delays.
Why It’s Hard to Treat
There is no single specialist for KMT2B because it’s still not fully understood. In fact, many clinicians have never seen a single case.
The disorder is diagnosed primarily through whole-exome genetic testing and confirmed through advanced tools like DNA methylation episignature analysis.
Who Should Be Involved in Treatment
Because KMT2B affects many systems, the ideal care team includes:
- Medical geneticist – interprets the mutation and helps plan follow-up
- Developmental pediatrician – tracks growth, learning, and delays
- Neurologist (movement disorders) – monitors dystonia and motor issues
- Speech-language pathologist – helps with speech and swallowing
- Occupational & physical therapists – support mobility and daily skills
- Child psychiatrist/psychologist – addresses behavior, emotion, anxiety
- ENT & audiologist – manage voice, swallowing, and hearing issues
- Orthopedic specialist – supports skeletal alignment and function
This is a team effort — and often requires parents to act as care coordinators.
What Treatments Are Available?
Right now, there’s no cure for KMT2B-related dystonia. However:
- Anticholinergic medications help in about 50% of cases
- Deep Brain Stimulation (DBS) has shown success in over 90% of treated patients
DBS targets a brain region called the globus pallidus interna. In one study, 27 of 29 patients treated with DBS showed major improvement, with some regaining the ability to walk independently.
Summary Table
| Category | Details |
|---|---|
| Discovery Year | 2016 |
| Reported Cases | ~246 with dystonia + 27 non-dystonic |
| Typical Onset | Childhood (~6 years) |
| Common Symptoms | Dystonia, speech loss, delays, hearing loss, psychiatric features |
| Treatment Options | Anticholinergics (~50%); Deep Brain Stimulation (90%+ effective in trials) |
| Multidisciplinary Team | Genetics, Neurology, Developmental Peds, Psychiatry, ENT, Audiology, Therapy |
Final Thoughts
KMT2B-related dystonia is one of the newest and rarest neurological disorders we know about. Because it was only discovered in 2016, we’re still learning what it means — and how best to help those affected.
Families are often left in the dark, bouncing between specialists and searching for answers that don’t yet exist. That’s why we share everything we’ve learned here: to shine a light for the next family navigating this same unknown road.
Disclaimer: I’m not a doctor—this is for informational and support purposes only, not intended to diagnose, treat, or rule out any medical condition. If you suspect a health issue, always consult a licensed medical professional.
Call to Action: Have a story about KMT2B? A tip or resource that helped your family? Click here to contact us — your voice can help someone else.
Author Bio: I’m Eric, a caregiver for my mom (an Addison’s warrior) and uncle to a beautiful 2-year-old niece diagnosed with KMT2B. I started Awareness4Rare to share the rare information I’ve found while fighting for my loved ones. If my words help even one person get a diagnosis faster or live a better life, this mission is worth every second.
