Fetal Gene Therapy Helps Mice with Spinal Muscular Atrophy

The animals lived longer and showed milder symptoms than untreated mice, although they didn’t survive as long as wildtype mice.

Written byAlejandra Manjarrez, PhD
| 4 min read
sma spinal muscular atrophy zolgensma in utero fetal gene therapy smn1

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ABOVE: Injection of the SMA gene therapy into one of the lateral ventricles of the brain of a mouse fetus
DR. GHOLAMHOSSEIN AMINI CHERMAHINI

Earlier this year, the US Food and Drug Administration approved the most expensive drug ever to hit the market, a gene therapy for spinal muscular atrophy. SMA is a neuromuscular disorder that, in severe cases, can lead to infant death. The genetic correction is currently used to treat affected newborns, but as symptoms for some types of SMA may appear before birth, an earlier treatment would be potentially more effective.

In a study published December 4 in Molecular Therapy, researchers were able to fix a mutation in the survival motor neuron 1 (SMN1) gene—which causes SMA in humans—in mice modelling the disease, while they were still inside their mothers’ uterus. The treated mice lived longer and had fewer symptoms than untreated animals.

Tippi MacKenzie, a fetal and ...

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Meet the Author

  • alejandra manjarrez

    Alejandra Manjarrez is a freelance science journalist who contributes to The Scientist. She has a PhD in systems biology from ETH Zurich and a master’s in molecular biology from Utrecht University. After years studying bacteria in a lab, she now spends most of her days reading, writing, and hunting science stories, either while traveling or visiting random libraries around the world. Her work has also appeared in Hakai, The Atlantic, and Lab Times.

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