Lina Zeldovich in Nautilus:
Most American newborns will arrive home from the hospital and start hitting their developmental milestones, to their parents’ delight. They will hold their heads up by about three months. They will sit up by six. And they will walk around their first birthday. But about 1 in 10,000 will not. They will feel limp in their caregivers’ arms, won’t lift their heads, and will never learn to sit on their own. When their alarmed parents seek medical help, the babies will be diagnosed with spinal muscular atrophy, or SMA, a neuromuscular disease in which certain motor neurons of the spinal cord progressively deteriorate. The disease is triggered by a genetic malfunction that boils down to the gene called SMN2 (survival motor neuron 2), which causes bits of vital proteins to assemble incorrectly, resulting in progressive muscle weakness and paralysis.
Until five years ago, this diagnosis wasn’t far from a death sentence. SMA was considered the most common genetic cause of infant mortality. Many babies with SMA didn’t live to celebrate their second birthdays. Some lived past their toddlerhood, but never grew strong enough to run around or play with other kids and eventually succumbed to the disease. But in 2016 that dire prognosis changed for the first time in history—thanks to a new FDA-approved therapeutic developed by Adrian Krainer, a biochemist at Cold Spring Harbor Laboratory, in collaboration with Ionis Pharmaceuticals and Biogen.