Joe and The Gene: A Mother's Perspective

Seeing Thomas Hunt Morgan’s experiments with fruit flies in episode one of The Gene: An Intimate History took me right back to ninth grade biology. My entire class of 14-year-olds paired up to carefully sedate swarms of fruit flies and group them according to their physical characteristics. Then we matched them up for mating and inspected their offspring to see which eye colors, stripe patterns and wing shapes had passed down to the new generation.

For many years, that was the extent of my interest in genetics.

Then came Joe. The only child of my husband and me, Joe is 11 years old, laughs a lot and loves to dance. Like a lot of 11-year-olds, he spends too much time on his iPad, ignores our directions and dawdles over dinner.

But Joe is also very different from most of his peers. He speaks only a few words, learns new things at a leisurely pace, needs help with tasks like climbing steps and opening doors, and is about the size of a child half his age.

Like Susannah, the...