A girl with spinal amyotrophy, a neuromuscular disease of genetic origin, was treated before birth by a medication, Risdiplam. Now aged 2 and a half, she still has no sign of pathology.
- American researchers have for the first time administered prenatal treatment against spinal amyotrophy (SMA), a serious neurodegenerative disease of genetic origin which is declared even before birth.
- A fetus at risk of SMA received risudiplam during the last six weeks of pregnancy. Two and a half years after his birth, the child has no symptoms of SMA.
- This pioneering study demonstrates the feasibility and safety of the approach, opening the way to new research to improve the early management of this disease.
Spinal amyotrophy (SMA) is a rare neurodegenerative disease of genetic origin which is declared even before birth. In the United States, it affects approximately one in 11,000. A team of researchers from the St. Jude children’s hospital in the United States has carried out an unprecedented scientific advance by administering, for the first time, prenatal treatment orally against this pathology. Two and a half years after birth, no symptoms characteristic of the disease has been detected in children. Unique cases details were published in the New England Journal of Medicine.
Hope for the prenatal treatment of SMA
SMA is due to a mutation in the SMN1 gene, which codes for the survival protein of motor spinal cord, essential to proper muscle functioning and therefore to movement. The disease occurs when both parents transmit to their child the deficient gene with which they are carrying. In its most serious form (type 1 SMA), as in the case of this little girl, it leads to progressive muscle deterioration and, in the absence of treatment, leads to death. Until now, existing treatments have improved survival and motor function of infants, provided that they are administered quickly after birth. The fact remains that these interventions do not allow to cure the disease.
In search of solutions, St. Jude researchers have designed a single clinical protocol to test the prenatal administration of a medication, Risdiplam, on a fetus whose parents had genetic mutations associated with SMA and who had already lost a child of this disease. A prenatal diagnosis by Amniocentesis had also confirmed the absence of the survival gene of motor neurons in the fetus, predicting a certain development of type 1 SMA.
The Risondiplam has been administered orally to the mother during the last six weeks of pregnancy. Usually prescribed after birth, it acts by modifying the expression of the SMN2 gene (cousin of SMN1) so that it produces more SMN protein. Result, at the birth of the little girl, “We have not observed any symptoms of SMA during exams”say scientists in a press release. The infant has certainly presented three developmental anomalies (a cardiac malformation that has been spontaneously resolved, hypoplasia of the optic nerve and asymmetry of the brainstem), but these were considered by researchers to have occurred at the start of fetal development, before exposure to the drug.
A revolution in the management of SMA?
Now two and a half years old, the child, who began to take treatment for eight days and will have to “probably” Taking it for life, always shows any signs of the disease. She has a “Normal muscular development without any sign of atrophy”specify researchers. This pioneer study therefore confirms not only the feasibility, but also the security of the prenatal approach. It opens the way to further research to determine whether an in utero intervention could indeed revolutionize the management of this disease.
