Chester Springs resident Dr. Andrew Freese, a renowned neurosurgeon and gene therapy pioneer, has died of kidney failure at 61, writes Valerie Russ for The Philadelphia Inquirer.

Freese was the first to perform a successful gene-therapy trial for neurological disease in a human being. Most recently, he was chief of neurosurgery and neurosurgical medical director at Brandywine Hospital.

He spent most of the past three decades as a neurosurgeon in the Philadelphia region, starting as a resident at the Hospital of the University of Pennsylvania. He later worked at Thomas Jefferson University Hospital, Graduate Hospital, and Einstein Medical Center, as well as in private practice.

In 2001, he performed an experimental gene-therapy surgery on a three-year-old boy who had Canavan’s disease, a rare genetic disorder that affects the brain. People with this disorder have a life expectancy of just 10 years. Thanks to Freese, his patient recently celebrated his 22nd birthday, becoming the longest-living person to survive with Canavan’s disease.

“All he wanted to do was help people,” said his son, Jack. “Growing up, that was my biggest takeaway from him.”

Read more about Dr. Andrew Freese in The Philadelphia Inquirer.