Floyd Hatch’s little brother was just 23 years old and seemingly healthy when his heart abruptly stopped and he “dropped dead” while playing football with a friend. Ten years later, Hatch said, his sister, 47, collapsed and died.

Hatch had run 41 marathons when, at age 64, his heart began to fail him. The culprit was plainly not lifestyle; Hatch had a dangerous genetic mutation that affects a protein in the walls of the heart. Further testing showed his 28-year-old daughter Courtney had it, too.

That information has helped Hatch and Courtney Hatch take precautions that could keep them from being blindsided by a heart attack — and administrators at Intermountain Healthcare say a new, extensive genetic study will make similar tests available at no cost to patients statewide.

"This has the potential to change the way we think of disease," said Intermountain CEO Marc Harrison.

Intermountain is seeking 500,000 patients who will provide two vials of blood each for genome mapping, to study links between people’s genes and their health on a scale doctors say hasn’t been done before.

“We will take that whole genome sequence and combine it with clinical outcomes to generate the largest-of-its-kind ... database that has ever been configured,” said physician Lincoln Nadauld, Intermountain’s chief of precision health.

There are other large genetic databases: In recent years, the National Institutes of Health and the U.S. Department of Veterans Affairs each sought 1 million participants for genetic analysis.

But what makes Intermountain’s study different is that the health system also is the participants’ health care provider, Nadauld said. That enables the researchers to track patients’ medical histories and outcomes in conjunction with the genetic information they provide, to identify “genetic determinants of health,” Nadauld said.

It also means doctors can access the patients’ genetic information to help make decisions that could help diagnose and address illnesses early on. Researchers believe 2% to 3% of the population has a genetic condition with a known association to some health problem, Nadauld said — but they aren’t being tested.

"I personally have grown tired of young patients showing up in our cancer centers with advanced breast cancer or colon cancer or some other kind of cancer that they inherited, and we could have known about that and prevented that if we had sufficient technology and understanding," Nadauld said.

Patients who participate can opt to receive the results of their genetic analysis and make plans with their doctors to preemptively address any red flags. They will come from Intermountain’s patient population, primarily in Utah and Idaho.

“We would like to better understand who those patients and families are so we can prevent the kinds of things that Mr. Hatch and his family went through,” Nadauld said. “We were able to find the genetic condition in his family, but it was only after two others had died. Wouldn’t it have been better if we had known beforehand?”

Floyd and Courtney Hatch each say their ounces of prevention have paid off. Courtney Hatch knows to visit the hospital when she feels any chest pain, and she has a heart monitor that allows doctors to see any irregularities in real time. They have noticed more irregularities lately, she said, and eventually she’ll probably need a pacemaker — but doctors will be able to install that before a potential heart attack.

"For me, I'd rather know [of genetic abnormalities] because I think it can only help you," she said.

Hatch carries an Apple watch to track his heart rate. His doctors have been able to coordinate his heart disease treatment with his treatment for the autoimmune disorder myasthenia. Three years ago, he was using a wheelchair, he said; now he is walking again. This week, he volunteered at a Scout camp and is helping his daughter build a fence at her house.

"There's been a huge improvement," he said. "My heart is actually mending a bit.

"We are so excited about this study because we think things like this are things that are going to give us as a family information that we need," he said.

The study, called “HerediGene: Population Study” is a partnership between Intermountain and deCODE genetics, an Amgen subsidiary based in Reykjavík, Iceland.

Although most of Utah’s population is not ethnically or racially diverse, Nadauld acknowledged, a lot of patients here have sprawling family trees — and that may actually help.

“It’s a significant advantage, because when you have multiple generations of information, then it’s easier to understand the genetic impact on the health of individuals,” Nadauld said. “So Utah is an outstanding population in which to conduct a study like this.”