Texas doctors treat siblings with condition like Charlie Gard's

HOUSTON, Texas -- Young siblings with the same genetic disease are making improvements every day, according to their parents.

Annabelle and Blair Elder are 6 and 5 years old, respectively, and were diagnosed with a mitochondrial disease several years ago after multiple trips to specialists. Their disease is similar to that of Charlie Gard, the terminally ill baby making headlines in England.

Mitochondrial disease is a genetic condition that affects the way the cells in the body create energy. As a result, patients often have trouble with muscle movements and balance.

Dr. Mary Kay Koenig, the director of the Mitochondrial Center of Excellence at McGovern Medical School at UTHealth, made the Elders' diagnosis.

Their parents, Elizabeth and James Elder, were relieved.

"It was like she just put the last piece in our puzzle and figured it out," Elizabeth said.

Dr. Koenig said diagnosing mitochondrial disease can be difficult. She said doctors didn't start identifying it until the 1980s, which is relatively recent in medicine.

"On a day-to-day basis, they may feel like they have the flu every day, with just kind of that lack of energy, that lack of ability to do the things they want to do. When they get sick, that just gets compounded and gets even worse," Koenig said.

Koenig said when some patients try to fight infections, key organs may not get enough energy to function properly. That's why an important part of treatment is preventing infections in the first place.

"Or if they do get sick, what can we do to help decrease their energy demands so that they can function better and survive that illness?" Koenig asked. "The better we get at that, the longer they live."

Annabelle and Blair will start experimental therapies in the next few weeks.