It's worse than that. The therapy likely killed her, and her condition wasn't fatal in the first place.
> Mei was diagnosed with global developmental delay .. some of Mei’s behaviors .. were associated with autism.
> CHD3 mutations produce a condition called Snijders Blok-Campeau syndrome
> people with the mutation often have a normal life expectancy, but their symptoms vary widely. Most have slightly larger than normal heads, and about two-thirds have intellectual deficits. Moderate to severe cases may be nonverbal, suffer from seizures and heart problems, and have fluid-filled voids in their heads.