This video excerpt from NOVA uncovers the genetic mystery that nearly killed Alexis, now 14, and introduces the debate surrounding genetic testing at birth. After diagnosing Alexis and her twin brother Noah with cerebral palsy at a young age, doctors later discovered that the twins shared a rare genetic mutation that led to a condition that mimics cerebral palsy. The twins improved after receiving treatment, but then Alexis took a turn for the worse. Thanks to whole genome sequencing, doctors discovered a second problem linked to the mutation and gave her a different treatment that saved her life.

This video is available in both English and Spanish audio, along with corresponding closed captions.