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.