Minnesota has added spinal muscular atrophy — a leading genetic cause of death in babies — to its newborn screening program now that a drug treatment for the disorder is available.

State Health Commissioner Jan Malcolm called it "an important move that will help save families from the heartbreak of losing a child or losing precious time where treating their child could result in better outcomes."

Unless parents decline testing, all babies born in Minnesota are now screened for the condition as part of a larger and long-standing newborn screening program, which takes blood droplets to test for 61 causes of childhood deaths and disabilities. SMA screening started March 1.

Spinal muscular atrophy involves the weakening and wasting of muscles due to a loss of brain motor neurons that are responsible for movement. Few treatment options existed until late 2016, when the U.S. Food and Drug Administration approved Spinraza, a drug injected into the fluid surrounding the spinal cord. In clinical trials, the drug slowed the progression of the disease and improved strength in 40 percent of the affected children.

Joining Malcolm on Monday to announce the screening was Carissa Kiester, a mother whose child had SMA and died two years before the drug was approved. She said she will always wonder if earlier diagnosis could have helped.

"It's so important to do this newborn screening so that we can know from day one, even before the symptoms kick in, and be able to give our kids the best chance possible," she said.

Minnesota's newborn screening program started in 1964 with checks for phenylketonuria, a disorder that requires patients to maintain strict diets to avoid buildups of an amino acid that can cause learning problems or brain damage. The screening program is one of the most comprehensive in the nation.

Privacy advocates and lawmakers have challenged the program at times over the past two decades over parental choice and the custody and use of blood samples after screening. The challenges resulted in changes in how long the state banks blood samples for testing and research.

Opponents unsuccessfully sought to convert the program to an "opt in" rule, so that newborns would be exempt unless their parents chose to have them screened.

Under the current system, all children are screened unless their parents sign forms opting them out.

Three states now universally screen for SMA. Others have awaited federal guidance, or more data on the long-term effectiveness of Spinraza, which has been controversial due to its cost — estimated at $750,000 in the first year.

The presence of any treatment offered for the first time against an incurable disease makes a persuasive case for screening, said Sondra Rosendahl, a licensed genetic counselor for Minnesota's newborn screening program.

"The reason not to do it [in the past] was that there was nothing we could do, even if we could find these children," she said.