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Thursday, November 19, 2020

Genetic Testing and Autism

In The Politics of Autism, I explain:
When a pregnancy is under way, doctors can detect certain kinds of disorders, but neither amniocentesis nor any other prenatal test can currently tell us whether a fetus will become autistic. Suppose that such a test did exist. “The best case use of a prenatal test at the moment would be if you could say to a parent, your child has got an 80 percent likelihood of autism and so once the baby's born, we would like to keep a close eye on that child in case they need extra support like speech therapy or social skills training or some sort of behavioral approach,” says leading autism scientist Simon Baron-Cohen. But would the “best case use” be the most common? When amniocentesis indicates Down Syndrome, most mothers choose abortion. A study of autism parents in Taiwan found that just over half would abort if a prenatal test indicated that their next child would be autistic. We cannot be sure what the figures would be if such tests were available in the United States, but it seems likely that a large share of autism pregnancies would end in abortion.

Sarah Zhang at The Atlantic:
For those with the money, the possibilities of genetic selection are expanding. The leading edge is preimplantation genetic testing (PGT) of embryos created through in vitro fertilization, which altogether can cost tens of thousands of dollars. Labs now offer testing for a menu of genetic conditions—most of them rare and severe conditions such as Tay-Sachs disease, cystic fibrosis, and phenylketonuria—allowing parents to select healthy embryos for implantation in the womb. Scientists have also started trying to understand more common conditions that are influenced by hundreds or even thousands of genes: diabetes, heart disease, high cholesterol, cancer, and—much more controversially—mental illness and autism. In late 2018, Genomic Prediction, a company in New Jersey, began offering to screen embryos for risk of hundreds of conditions, including schizophrenia and intellectual disability, though it has since quietly backtracked on the latter. The one test customers keep asking for, the company’s chief scientific officer told me, is for autism. The science isn’t there yet, but the demand is.

The politics of prenatal testing for Down syndrome and abortion are currently yoked together by necessity: The only intervention offered for a prenatal test that finds Down syndrome is an abortion. But modern reproduction is opening up more ways for parents to choose what kind of child to have. PGT is one example. Sperm banks, too, now offer detailed donor profiles delineating eye color, hair color, education; they also screen donors for genetic disorders. Several parents have sued sperm banks after discovering that their donor may have undesirable genes, in cases where their children developed conditions such as autism or a degenerative nerve disease. In September, the Georgia Supreme Court ruled that one such case, in which a sperm donor had hidden his history of mental illness, could move forward. The “deceptive trade practices” of a sperm bank that misrepresented its donor-screening process, the court ruled, could “essentially amount to ordinary consumer fraud.”