Study: Saliva Test Can Detect SMA

Scientists in Japan have found a new, non-invasive way to test for spinal muscular atrophy (SMA).

As published in Genes,Detection of Spinal Muscular Atrophy Patients Using Dried Saliva Spots” could offer an additional way to test newborns.

In an October news announcement, the team of scientists said, “Confirmed diagnosis by SMN1 [Survival Motor Neuron 1] testing is often delayed, suggesting the presence of diagnosis-delayed or undiagnosed cases. To enable patients to access the right treatments, a screening system for SMA is essential. Even so, the current newborn screening system using dried blood spots is still invasive and cumbersome.”

Researchers found that using dried saliva spots as a DNA source rather than blood worked well to detect the deletion of the SMN1, which the scientists said accounts for more than 90 percent of SMA cases.

SMA can now be treated by a trio of drugs, but “These drugs give better outcomes when treatment is initiated at an early stage, before the onset of symptoms,” the study said. “Therefore, there is a growing implementation of newborn screening programs for SMA worldwide.”

Older children or even adults with milder forms of SMA might not be diagnosed until much later in life, the researchers added. Screening for SMA using saliva could be accomplished in a number of everyday settings, including schools, workplaces and homes. Saliva-based procedures could be much easier to carry out than blood-based testing, which would require the involvement of healthcare professionals.

Researchers concluded that SMA screening using saliva samples could be “a good alternative source for SMA detection. The sample collection procedure is non-invasive, easy to handle, and requires no hospital visitation.”

Such screening “might be preferable for SMA screening for older children or adults. We hope that this will help in overcoming the delay in SMA diagnosis.”


About the Author

Laurie Watanabe is the editor of Mobility Management. She can be reached at

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