Scientists say they can read nearly the whole genome of an IVF-created embryo

^{Photo by ZEISS Microscopy on Flickr}

A California company says it can decipher almost all the DNA code of a days-old embryo created through in vitro fertilization (IVF)—a challenging feat because of the tiny volume of genetic material available for analysis. The advance depends on fully sequencing both parents’ DNA and “reconstructing” an embryo’s genome with the help of those data. And the company suggests it could make it possible to forecast risk for common diseases that develop decades down the line. Currently, such genetic risk prediction is being tested in adults, and sometimes offered clinically. The idea of applying it to IVF embryos has generated intense scientific and ethical controversy. But that hasn’t stopped the technology from galloping ahead.

Heart conditions, autoimmune diseases, cancer, and many other adult ailments have complex and often mysterious origins, fueled by a mix of genetic and environmental influences. Hundreds of variations in the human genome can collectively raise or lower risk of a particular disease, sometimes by a lot. Predicting a person’s chance of a specific illness by blending this genetic variability into...