TK2d Awareness Day 2026:
Stories that need to be heard
TK2d Awareness Day takes place on Tuesday 8 September 2026.
Launched in 2022, TK2d Awareness Day is a global initiative dedicated to raising awareness of thymidine kinase 2 deficiency (TK2d)—an ultra-rare, debilitating and life-threatening mitochondrial disease (mito). The day brings the TK2d community together to improve understanding, amplify the voices of those affected and highlight the need for diagnosis, support and research.
This year, we are sharing three personal stories from the TK2d community. Each film offers a powerful perspective on life with TK2d and shows why greater awareness matters.
Lacey’s story, shared by her mum Lisa
Lisa shares the story of her precious daughter, Lacey, who lived with TK2d.
She describes knowing that something was wrong, fighting to have her concerns heard by doctors and experiencing the devastating loss of her beautiful little girl.
Lisa is bravely telling Lacey’s story to raise awareness of this devastating disease and help other children and families affected by TK2d.
Watch Lisa and Lacey’s story
Vivian’s story
Vivian, from Brazil, shares her experience of living with TK2d and finally receiving a diagnosis at the age of 35.
After years of uncertainty, having a diagnosis helped Vivian understand her condition. She also speaks about her hopes for the future and the difference an experimental therapy has made in her life.
By sharing her story, Vivian hopes to increase awareness of TK2d and help others feel less alone.
Aneesa’s story.
Aneesa’s story is coming soon.
Follow us on social media or return to this page to hear her experience and help us continue raising awareness of TK2d.
TK2d International Webinar 2026
The TK2d International Webinar 2026 will take place on 9 September 2026, bringing together the international TK2d community to share knowledge, strengthen collaboration and raise awareness among healthcare professionals. The preliminary programme is now available to download, with further speakers to be confirmed as the faculty is finalised. The webinar will provide an important opportunity to connect experts and the wider TK2d community and explore diagnosis, multidisciplinary care and therapeutic progress.
Click here to register
Download the Preliminary Programme
New hope for the TK2d community
The approval of the first therapy for TK2d by the United States Food and Drug Administration (FDA), followed by a positive recommendation from the European Medicines Agency (EMA), has brought new hope to the TK2d community.
Clinical studies demonstrated significant benefits for eligible patients, including improvements in motor function and survival, outcomes that have had a life-changing impact on patients and their families.
However, regulatory approval does not automatically guarantee that every eligible patient can access the therapy. IMP will continue to advocate for equitable access for people with TK2d around the world.
Help raise awareness
You can make a difference this TK2d Awareness Day.
Share these films on social media, tell your community about TK2d and mito and encourage others to join the conversation. Every post and every share can help more people learn about this ultra-rare disease and ensure that the voices of those affected are heard.
Editable social-media posts and other campaign materials are available in the resources section of our World Mitochondrial Disease Week page.
Download the resources and help us raise awareness on Tuesday 8 September 2026.
Watch the full film
Lisa, Vivian and Aneesa’s stories were originally brought together in this powerful film featuring three voices from the TK2d community.
Together, their experiences demonstrate the importance of listening to families, finding answers and creating hope for everyone affected by TK2d.
TK2d Day (Italiano)
TK2d Day (Français)
TK2d Day (LatAm Spanish)
TK2d Day (Brazilian Portuguese)
TK2d Day (Spanish)
What is TK2d?
TK2d, or thymidine kinase 2 deficiency, is an ultra-rare primary mitochondrial myopathy that causes progressive muscle weakness associated with debilitating and life-threatening symptoms, including, difficulty breathing, limited mobility, and challenges eating and swallowing.
A factsheet was created in partnership with the TK2d community that can be found here:
Due to the complexity, progressive nature and the wide range of symptoms TK2d can cause a multi-disciplinary health team is needed to manage the care of patients.
Together with mito we can Take on Tk2d
A brochure developed by UCB Biopharma in collaboration with the United Mitochondrial Disease Foundation and The Jeremiah Gracen Foundation that provides a comprehensive overview of thymidine kinase 2 deficiency (TK2d), a rare mitochondrial disease that causes progressive muscle weakness and can affect walking, eating, and breathing. Inside, you’ll find information on the causes of TK2d, its symptoms across different ages, the importance of early and accurate diagnosis, and the role of a multidisciplinary healthcare team in managing the condition. It also highlights patient perspectives and lists organizations and resources available to families and individuals impacted by TK2d.
Click on the image to download the brochure.
From One Caregiver to Another – A Shared Journey Through TK2d
This caregiver guide shares real-life stories and reflections from those caring for people with TK2 deficiency. It offers emotional support, tips for daily care, information about treatment options, helpful resources, and encouragement for caregivers navigating this rare disease alongside their loved ones.
Global
US Spanish
Who does it affect?
TK2d is a mitochondrial DNA deletion/depletion syndrome that affects children and adults and is confirmed by genetic testing.
Today the exact number of people with TK2d is unknown. In 2018, there were about 107 individuals reported in the medical literature with this condition.* Because TK2d was first described in 2001 and is not a well-known cause of muscle weakness, it is likely that TK2d is underdiagnosed. Other myopathies that look like TK2d include Pompe, Limb Girdle Muscular Dystrophy, Kearns Sayre Syndrome (KSS), and CPEO.
*For the original source of this information, click here.
Where can I get more information?
There are a number of excellent sources of information available on Orphanet and our member websites:
TK2d Awareness day
In 2022, together with our partners, we launched the first world TK2d Awareness Day. The purpose of this day is to raise awareness of this rare but debilitating disease. The day forms part of the calendar of events included in World Mitochondrial Disease Week, and falls on the second Tuesday of September every year.
TK2d Awareness Day will be on Tuesday 8 September 2026
For more information visit Mitochondrial Disease Week.
Rare but worth the share
TK2d has only been recently characterised, so its rate of occurrence is unknown. Being a rare disease, the symptoms are often misdiagnosed. To increase awareness of the symptoms of TK2dD, IMP collaborated with UCB (formally Zogenix) to produce an infographic which we call ‘Rare but worth the share’. We’d love for you to use this and share it on your platforms.
Download the 'Life with TK2d' infographic
