been different if she’d had the option of treatment in utero.
“You see your nephews and nieces growing up and her stuck
at a certain level,” he says. “We missed the opportunity of
treating her early.”
Of the 10 compounds that Guedj and Bianchi identified, two
seem particularly promising. One is apigenin, which is found
in plants, but Bianchi won’t yet publicly identify the other.
Each has shown therapeutic, but not groundbreaking, effects.
No matter how successful the drugs might be, Bianchi does
not expect them to change the physical appearance of people
with Down syndrome; nor is it likely that they’d reduce the
incidence of heart defects, which occur in about half of babies
with the disorder. “From what I’ve seen so far, there is no
magic bullet where you take the drug and everyone is cured,”
Some researchers, however, are contemplating more radical measures. Jeanne Lawrence, a professor in the Department of Cell and Developmental Biology at the University of
Massachusetts, made headlines in 2013 when she succeeded
in “silencing” the extra copy of chromosome 21 in human cells
from a patient with Down syndrome. She did so by using gene
editing to splice in a gene for an RNA coating that painted the
extra chromosome with a molecular block so that none of its
250 genes produced any proteins.
To Lawrence, this is a first step toward a “chromosome
therapy” that would make use of genetic engineering in the
womb. “Multiple pathways are perturbed, and one drug is not
enough to fix them,” she says. “If you can silence the 250 genes,
you don’t need a drug.”
Fetal gene engineering probably remains far off. But the
first prenatal tests of drugs in humans are likely to start soon.
A group of physicians at University of Texas Southwestern in