For most of his life, Connor Dalby couldn't walk.
As a baby, he spent much of his time in hospitals, hooked up to machines while doctors tried to figure out what was happening to him.
His mother, Kelly Del Real, remembers those early years as a constant cycle of seizures.
"It was around the clock. So 50 to 100 seizures a day, all day, all night."
Dalby was eventually diagnosed, when he was almost 5, with a rare genetic form of epilepsy caused by a mutation in the SCN2A gene.
The condition is known as SCN2A-related developmental epileptic encephalopathy, or DEE.
It's part of a group of rare disorders in which seizures are just one piece of the puzzle. The abnormal brain activity can also interfere with development, movement, communication and everyday functioning.
Dalby's family tried medication after medication.
"He's trialed over 12 or 13 different anti-seizure medications," Del Real said. “And nothing really helped very much."
By the time he was 14, he still couldn't walk on his own. He relied on a stroller or wheelchair to get around.
There was no genetic therapy available that could target the specific mutation causing his disease.
Dalby's mutation is particularly complicated, said Dr. Olivia Kim-McManus, a UC San Diego neurologist who treated him at Rady Children's Hospital.
"He carries a more complex variant that requires an allele-selective approach because he has both seizures and autism," she said.
So Kim-McManus and her team took a different approach.
They worked with n-Lorem Foundation, a nonprofit that develops personalized medicines for people with ultra-rare genetic diseases, to create a treatment designed specifically for his mutation.
Unlike medications that treat the symptoms of a disease, this personalized treatment was designed to target the specific genetic mutation causing his condition. She said the hope is that by targeting the underlying genetic problem, the treatment can change how the disease affects him.
Dalby received his first dose at 14.
The treatment was administered at Rady Children's Hospital through the spinal fluid, and Dalby has continued receiving doses as researchers monitor his progress.
The treatment is still investigational, but his family was willing to try.
"We're going to give it a shot. There wasn't a doubt in my mind," Del Real said.
Then, about four months after his first dose, something happened that his mom had never seen before.
"He started trying to take steps unassisted. So the first time in his entire life," she said.
Today, Dalby can walk about 50 or 60 steps on his own, his mom said. He's sleeping better. His behavior has improved. And his seizures have been reduced by 90 percent.
"It's totally changed our quality of life,” she said. “And given him certain skills and a level of independence that he did not have before."
Dalby is 17 now. And he's finally getting to do something he hasn't really had the chance to do before. Be a teenager.
“I got to take him on his first roller coaster. It was the best moment ever,” Del Real said. “Just something that we never thought he would be able to handle.”
The research documenting his treatment and progress was published in the journal Nature Medicine this month.
For Kim-McManus, Connor's case raises a much bigger question about the future of medicine.
Could doctors develop treatments tailored to the specific genetic mutations causing rare diseases, even when there is no existing therapy?
Kim-McManus said the answer is still being worked out.
Bringing personalized genetic medicines to more patients will require research and funding.
But Dalby's case offers a glimpse of what that future might look like.
"It's hard to deny what we were seeing at the beginning,” Kim-McManus said. “So that was very exciting and hopeful."
Dalby's mom says her son is already helping pave the way.
"He was the first human ever to be treated with this molecule,” she said. “I tell him all the time how many families and kids that he's helping."
She said the hope is that what researchers learned from treating one child could eventually help many more.
