Joseph Hann feels his mother’s comforting touch and hears the soothing sound of her reading one of his favorite stories at his bedside. He occasionally smiles and bobs his head in approval, and at one point tries to sing along to a musical passage.

But the 6-year-old cannot form syllables, nor can he see the words on the pages of the book near his lap. A tiny wheelchair sitting in the corner hints at just how much he has lost as a deadly genetic disease – CLN7 – continues to ravage his nervous system.

It’s heartbreaking to see your child go through this, said Gina Hann, Joseph’s mother. But he still has his same personality, his same joy. And we’re still expecting JoJo can beat this disease.

Mrs. Hann’s optimism stems from advancements being made by a gene therapy program at UT Southwestern where leading experts are engineering innovative treatments for some of the world’s rarest neurological diseases. By inserting healthy genes missing from patients’ DNA, scientists are looking to develop lifesaving treatments for children who suffer from rare genetic conditions that are traditionally difficult to treat.

To read a full version of this story, view it in the UT Southwestern Newsroom.