24/04/2025
A baby who was destined to inherit a fatal genetic disease was cured while still in the womb.
This child, now almost three years old, shows no signs of spinal muscular atrophy (or SMA), a debilitating and often fatal motor neuron disease, after receiving treatment before birth.
SMA affects the motor neurons, leading to progressive muscle weakening and is a leading genetic cause of death in infants and children. In its most severe form, individuals lack both copies of the SMN1 gene, relying on limited copies of the SMN2 gene, which partially compensates for the deficiency. This results in insufficient production of the SMN protein, crucial for maintaining motor neurons, particularly during the second and third trimesters of pregnancy and the first few months of life. Babies with severe SMA often do not survive past their third birthday.
Previously, treatments for SMA were administered after birth, but this approach had limitations, as many affected newborns already exhibit symptoms at birth. This particular child was diagnosed with SMA type 1 in utero, the most severe form of the condition, as both copies of the SMN1 gene were affected. Given the family's history of losing a previous child to the same condition, the medical team sought and received FDA approval to administer risdiplam, an oral drug that modifies the expression of the SMN2 gene to increase SMN protein production, prenatally. During the last six weeks of pregnancy, a critical period for SMN protein development, the mother received daily doses of risdiplam while being closely monitored. After birth, the child continued to receive the medication orally. The results have been remarkable: the child, now nearly three years old, has shown no signs of SMA. While the child may require lifelong treatment with risdiplam and ongoing monitoring, the treatment opens doors for further research into prenatal therapies and offers a new paradigm for managing genetic diseases before birth.
learn more https://www.nature.com/articles/d41586-025-00534-0
