Most babies who are screened for SMA will have a negative result. A screen negative result means that a baby has a low risk of having the disease and follow-up diagnostic testing is not needed based on these results.
A small number of babies will have a screen positive result for SMA. It is expected that approximately 15 babies will have a screen positive newborn screening result for SMA each year in Ontario. A screen positive result for SMA means there is a high risk for SMA. Infants with a screen positive results will be referred for follow up.