MED 23 gene defect became familiar to Jillian Clegg in May of 2013. 

After more than a decade seeking answers for her sons Tyler (born in 2002) and Luke (born in 2008), Clegg finally was able to put a name to the previously undiagnosed condition that two of her four children have. 

Five months after Tyler was born, the Clegg’s realized that he was not meeting the developmental milestones that other children in his age group were. Tyler screamed and slobbered a lot, seemed sick, and did not have purposeful eye movements. 

Tyler Clegg, photo courtesy of Jillian Clegg

After taking Tyler to multiple neurologists whose tests were consistently inconclusive, Clegg realized that it was up to her to fight for her child.

Tyler was subject to tests, procedures, surgeries and blood draws throughout his young life. Many came back normal or inconclusive, prompting one neurogeneticist to state that they would probably never know what was causing issues for Tyler. 

During this time, Tyler got to welcome one little brother, Noah, followed by the birth of twin brothers, Luke and Aiden. After observing Luke’s developmental process, Clegg intuitively knew that Luke had the same condition Tyler did, and she realized the cause of Tyler and Luke’s condition had to be genetic.

Luke Clegg, photo courtesy of Jillian Clegg

When Clegg learned of the National Institute of Health’s (NIH) Undiagnosed Diseases Program, she wasted no time in applying. The Undiagnosed Diseases Program uses science and medicine in order to provide answers to those whose conditions have been undiagnosed while advancing medical knowledge around rare diseases. Using experts from many different fields across different NIH offices, the Undiagnosed Diseases Program brings families to the NIH offices to undergo evaluation. For a week, the Clegg family underwent tests and appointments in hope of diagnosing Tyler and Luke.

Three years after undergoing testing at the NIH, the Clegg family finally received their diagnosis in May 2013. 

MED 23 gene defect is an autosomal recessive neurological condition characterized by intellectual delays. Symptoms include difficulty swallowing and eating, gastrointestinal complications, screaming spells, and reflux symptoms in infancy, inability to read, write, speak, walk, or use arms in a purposeful manner, high muscle tone in arms and legs, sensory issues, and normal height and weight with no physical malformations. 

MED 23 gene defect is new to medical science. The Clegg family joins one other known family worldwide with this condition, and the only known heterogeneous occurrence of MED 23. 

Jillian Clegg started Hope 4 Tyler and Luke before she obtained the diagnosis for Tyler and Luke with the goal of getting information out in the world for families with the same condition to be identified and brought to research. So far, not many have crossed Clegg’s path that may also have MED 23, but Clegg is hopeful that with constant media exposure, another family will be able to alleviate the stress of not knowing and finally have a diagnosis for their child. 

Tyler and Luke are extremely happy boys who love to be around other kids. While they are unable to talk, walk, feed themselves, or communicate, the Clegg’s are working on iPad communications for the boys. They have limited mobility (Luke can roll and Tyler can bunny-hop) and require constant supervision and assistance but are always smiling and fun to be around. 

Tyler and Luke, photo courtesy Jillian Clegg

MED 23 is a progressive white matter disease, which for the Clegg boys means that with physical and cognitive therapy and education, they have been able to make improvements in their motor skills. Tyler has learned to walk with a platform walker (must be steered and nudged in the right direction) and explores his environment as much as possible through his means. Luke is starting to balance himself and is making attempts to stand and bear weight. 

The tireless work of parents to challenge what is told to them by some and fight for their children is astounding. As stated by CNS Foundation co-founder Fia Richmond, ” When the medical community told me that nothing could be done for Palmer, I realized that what I really needed was a scientist.” Clegg is a parent that shares this fighting spirit, and as such, serves as a beacon to those that have been told there is simply nothing they can do. 

Jillian is hopeful for the future of her children. Tyler and Luke are immensely supported by their brothers, their family, and their Pennsylvania community. Thanks to scientists at the NIH, they have a name for their condition and continue to search for other families that may also be affected. 


To learn more about MED23 gene defect or to stay updated on Tyler and Luke, visit their website, Hope4TylerandLuke.

To learn more about the NIH Undiagnosed Diseases Program, visit this blog