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Newborn Screening Ontario
Spinal Muscular Atrophy


Spinal Muscular Atrophy Overview

Spinal muscular atrophy (SMA) is a rare inherited (genetic) disease.  SMA results in muscle weakness and atrophy (muscle wasting).  There are 4 main types of SMA depending upon the age of symptom onset and the highest level of motor skills (for example sitting, crawling, walking) that the baby or child is able to achieve.  Many babies with SMA will not have any symptoms at birth.  Treatment has recently become available for babies with SMA and is effective.  Without treatment the more severe, early onset forms of SMA (in particular SMA type 1) will lead to death in the first year or two of life.

Starting in January 2020, the blood collected from the heel prick will be used to screen for SMA.  A screen positive result means that there is a high risk for SMA.  Babies identified at a young age through screening can be treated as early as possible.  This is why newborn screening for SMA is being offered. 

SMA is one of the first conditions to be phased-in through a pilot period in Ontario over the first few months in 2020 before it is expected to be formally added to the list of diseases screened in Ontario.  One reason it is being run as a pilot is that treatment has recently become available for this condition.  Screening babies as soon as possible (in the form of a pilot) means that more babies with SMA can be identified and started on treatment now.  As well, phasing in screening allows time to develop regulatory and policy changes required in the province. 

Babies who have their blood taken for dried blood spot screening in Ontario will also be screened for SMA.  Families that decline dried blood spot screening will not be eligible for SMA screening.