Janell and Elliot Lewis had no idea there was anything wrong with their first daughter, Blakeley, until weeks after she was born in 2011. That’s when the Ogden couple noticed their new baby hardly moved, Elliot recalled, and that her arms looked “floppy.”

Blakeley was eventually diagnosed with spinal muscular atrophy, or SMA, a rare but usually fatal disease that is the leading genetic cause of death for infants. Like most infants with SMA at the time, Blakeley’s motor functions crumbled, and she died before her second birthday.

There was no treatment to save her. But there is now, after the U.S. Food and Drug Administration approved a drug known as Spinraza in late 2016.

That breakthrough has prompted the Utah Department of Health this week to start testing all newborns in the state for SMA, adding it to 40 other genetic disorders for which Utah babies are now routinely screened.

The new test — conducted using a blood draw shortly after birth — could save the five or six Utah infants born with the disease each year, health officials said Wednesday at the Unified Public Health Laboratory in Taylorsville. So far, Massachusetts is the only other state testing for SMA, which affects one in 11,000 infants nationwide.

“There may not be any sign a newborn is sick until there is irreparable harm,” Kim Hart, a manager with the Utah Department of Health’s Newborn Screening Program, said of the disease.

After losing Blakeley, the Lewis family wanted to try to have another child. Knowing the infant would be at risk of SMA, the couple opted for early testing, before their daughter Evie was born last April.

“Unfortunately,” Elliot said, they “got the confirmation that she also had the disease.” But this time, they were prepared — and a new drug treating the condition was on the market.

Evie began receiving Spinraza, which also goes by the generic name Nusinersen, 12 days into her life, in an effort to fend off any loss of motor function, such as walking, eating and breathing.

Made by drugmaker Biogen at a cost of $125,000 per dose, the treatment must be delivered via a spinal tap as many as four times in the first two months of life, then once every four months after that, said Russell Butterfield, a University of Utah neurologist and SMA expert. Insurance companies, including the Lewis’, are covering the drug.

“You can see the outcome is just drastically different,” Butterfield said.

At Wednesday’s event, Evie happily sat with her parents, acting just like any healthy baby might: waving around her arms and staring at several cameras clicking nearby.

Even with the treatments for SMA, there remain some “lingering effects” from the disease, Butterfield said, but only a medical expert would spot them.

U. scientists had helped conduct trials on the new drug before it was released. And it was U. officials who signaled to the state that an SMA screening for Utah’s 50,000 newborns each year would be worthwhile, now that there was a way to treat it, Butterfield said, who added that less invasive SMA treatments are also under development.

Health providers draw blood samples from Utah newborns from their heel. Portions of those samples, accompanied by the child’s demographic information, go to the Newborn Screening Lab in Taylorsville, where they are processed and tested by a team of about 20 technicians and scientists within days of the birth.

The lab also recently deployed new handling machinery to help process the SMA tests more efficiently, laboratory director Andy Rohrwasser explained during a tour of the facility.

Having SMA screening in place, Elliot Lewis said, is “the difference between life and death for these kids.” And his daughter Evie, he said, is “the living embodiment of that.”