In China, some parents seek an edge with genetic testing for tots

In Shenzhen, even kindergartners have homework. You can see it in the workbook-laden backpacks weighing them down as they waddle through the school gates at 8 a.m. and back out again at 5 p.m. Many are not headed home yet. There are dance classes, piano lessons, English tutors, kung-fu sessions to get to. After classes, after dinner, it is time to tackle that homework. They are lucky to get to bed by 10.

Fears of seeing their children fall behind their peers have left Chinese parents searching for anything to give them a leg up.

Some are now turning to genetic testing companies that claim they can find children’s hidden talents within their DNA. There isn’t much scientific basis to the tests, but judging from the number of clinics sprouting up in cities like Shenzhen, it appears that “talent testing” is one reason for China’s fast-growing genetics industry.

I visited the office of China Bioengineering Technology Group (also called CBT Gene) on the 14th floor of a high-rise in Shenzhen’s Nanshan startup district. It is half medical clinic, half high-end...