Early screening for spinal muscular atrophy in babies could be life-altering

Denise Deveau Postmedia Content Works 4 minute read February 1, 2020

Destiny McCalvin had her son Chance tested after losing a child

When Destiny McCalvin was pregnant with her son Chance, she and her husband Justin had every reason to be concerned. Two years earlier they had lost their daughter Kensley to spinal muscular atrophy (SMA) at the age of seven months.

When her daughter was diagnosed at five months, it was the most horrible news any parent could face, McCalvin said. “She had a fatal disorder that we couldn’t do anything about.”

SMA is the result of a genetic mutation that leads to devastating outcomes. Like other genetic mutations, the parents can be carriers without knowing it.

Genetic testing on the McCalvins confirmed that they were both carriers, so their children would have a one in four chance of being born with Type 1 SMA – the most debilitating and rapidly progressing category of the disease that affects one in 10,000 births per year.

The deterioration for Type 1 sufferers begins very early, but the signs are not evident until about three to six months, which is when some parents will begin to notice. Awareness of SMA is key so parents are quick to follow up when the baby is not reaching its milestones.

“It’s a heartbreaking condition to watch,” said Dr. Alex MacKenzie, pediatrician at Children’s Hospital of Eastern Ontario in Ottawa. “Most Type 1 patients succumb to the disease by two years of age, because the muscles involved in breathing are also affected. Types 2 and 3 come on later and progress more slowly. People are more familiar with a similar neurodegenerative disorder that more commonly affects adults – Lou Gehrig’s disease or ALS.”

The gene at the root of SMA was discovered in the early 90s. “For 95% of patients with SMA, the SMN1 gene primarily responsible for producing the proteins to develop motor neurons and other cells is mutated or absent,” Dr. MacKenzie explained.

Families have no way of knowing if their child will have it unless they have gone through genetic pre-screening, or like the McCalvins, already had a newborn with SMA, he adds. “There is usually no family history, so the diagnosis is like a bolt out of the blue.”

Unfortunately, McCalvin’s amniocentesis at 16 weeks confirmed that the new baby would also be born with Type 1 SMA. It was devastating to hear, but she was ready to take on the challenge. “The news wasn’t good, but I was determined to do something about it. Just because people say there is nothing you can do; it doesn’t mean it’s true.”

She turned to online SMA communities to explore options and gather feedback. “All kinds of people commented. I started finding out a lot about research. I knew that SMA causes motor neurons to decrease every day your child is growing, so time is a factor.”

There is no cure for SMA, but with early detection, physical therapy and a variety of medical devices, the quality of life may be improved.

The importance of early screening should not be underestimated, Dr. MacKenzie said. “This is a disease where deterioration can begin to affect infants from birth. He is among a number of practitioners who have lobbied to include SMA screening in the first week of life for babies.

McCalvin said she is grateful to have had a chance to fight for her child’s survival and keep her late daughter’s legacy alive. “I want to scream to the world that without newborn screening you have watch that your baby is meeting milestones. Because we knew what we were dealing with we were proactive very early on and gained the awareness to take the initiative, we were able to get our son help.”

Spinal muscular atrophy is not part of routine newborn testing in Canada. Parents need to be aware of signs of the disease, such as motor delays and missing developmental milestones. A comprehensive list of signs and symptoms of SMA, as well as questions to ask your doctor are available at Together in SMA.

This story was created by Content Works, Postmedia’s commercial content division, on behalf of a research based pharmaceutical company