Healing Molecule Snippets
Antisense therapies lived in the shadows for a long time, but now they are achieving spectacular medical success. However, they come at a price.
Emma Larson couldn't walk or stand on her first birthday, but that wasn't a concern - a lot of other kids that age can't either. Emma loved her baby bouncer and loved crawling around her parents' apartment in Long Island, New York. But a little later, at the age of 13 months, her legs suddenly stopped working. "It came like a snap of your fingers," says her mother, Dianne Larson. Emma stopped bouncing and buckled helplessly whenever she tried to pull herself up anywhere. There was also a change in the way she crawled - more subtle, but when her parents watched an older video, the difference was obvious. The girl's range of action had shrunk and she was struggling to keep her head up.
After an odyssey of medical tests, the Larsons learned in July 2014 that Emma had Spinal Muscular Atrophy (SMA). This is a potentially fatal neurodegenerative disease that primarily affects children and gradually robs them of the ability to walk, speak and, in severe cases, breathe. Emma's motor neurons in her spinal cord died, caused by a lack of a protein called SMN (Survival Motor Neuron) in her body. "When your child receives a diagnosis like that, you step through the darkest abyss," recalls Dianne. But the family did not give up. "We were willing to do just about anything to fight this terrible disease," says Matt Larson, Emma's father.
Not far from the Larsons' home, at Cold Spring Harbor Laboratory, biochemist and molecular geneticist Adrian Krainer was caught up in the same struggle. He had been studying the genetic basis of SMA since 2000 and knew that the cause of the disease is a missing or mutated gene called SMN1. At the same time, it was known that all humans have an inactive counterpart to this gene called SMN2 that could possibly be activated. In 2004, Krainer partnered with Frank Bennett of Ionis Pharmaceuticals to develop a drug that causes SMN2 to make SMN proteins functional. The goal: alleviate the symptoms of SMA patients and stop the progression of the disease. To do this, the researchers turned their attention to so-called antisense oligonucleotides …
