Teegan is Kelly and Matt Olson’s youngest daughter, so when she began missing developmental milestones, her parents were on alert. After a variety of tests over the span of her life, doctors diagnosed Teegan with myocyte enhancer factor 2 (MEF2C) haploinsufficiency syndrome caused by rare MEF2C gene mutations.

This condition, known as MEF2C for the affected gene or MCHS, only affects around 350 people worldwide that we know of. However, it could be undiagnosed in many individuals as well. As of right now, there is still a limited understanding of MEF2C mutations and their impact.

Teegan currently cannot walk or speak independently. However, her therapy sessions have helped her to gain skills; she is starting to eat and stand more on her own.

According to Pauleen Le of CBS Minnesota, the Olson family is now striving to raise awareness and cultivate a deeper understanding of MCHS. Right now, there are no cures for this disorder. Kelly joined the US MEF2C Foundation’s parent board to begin pushing for increased research and awareness. They hope that this mission will help not only Teegan, their happy, bubbly nearly-two-year-old, but other affected children and families. 

What’s Known About MEF2C Haploinsufficiency Syndrome 

MEF2C haploinsufficiency syndrome is an emerging neurodevelopmental disease caused by MEF2C gene mutations. Normally, this gene encodes for the production of the MEF2C protein; this protein plays a role in musculoskeletal, immune, cardiovascular, neurological, and craniofacial function. These mutations, which often include a deletion of genetic material, mean that the body does not produce enough of this protein. Typically, symptoms of this condition appear between ages one and two. Symptoms may include:

• Global developmental delays
• Severe hypotonia (low muscle tone)
• Impaired or absent language
• Poor coordination and an unsteady gait
• Severe gastroesophageal reflux disease
• Strabismus (crossed eyes) 
• Feeding, sleeping, and learning difficulties
• Muscle spasms
• Ventricular septal defects
• Duplex left kidney
• Hypermobility
• Brain abnormalities such as enlarged ventricles, brain cell loss, or an abnormal corpus callosum
• Head-nodding, teeth clenching, hand clapping or wringing, or tongue thrusting
• Seizures

Learn more about the varied symptoms of MCHS here.