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 child we met in episode 1, Joe was the product of a healthy pregnancy and a relatively uncomplicated birth. He was an easy newborn, sleeping soundly and enjoying his waking hours with hardly a fuss. All was well and my husband and I saw nothing but smooth sailing for our baby’s life.
But then, he began falling behind on the milestones every parent eagerly awaits. He wasn’t tracking objects with his eyes or reaching for them. He wasn’t able to push up on his arms or even hold his head very steady. He smiled mostly at lights, not faces or toys. He wasn’t growing at the expected rate, despite a healthy appetite.
This sent us on an odyssey of specialist visits: endocrinologists, ophthalmologists, developmental pediatricians, neurologists. They tested for some very scary conditions, and all of those tests came back negative. We were delighted not to have a frightening answer but frustrated to have no answer at all.
All of these question marks led us to a geneticist at VCU Health, who noted that Joe’s difficulties involved multiple systems: his vision, his growth, his cognitive function and his motor skills. This “constellation of issues,” she said, suggested that he has a genetic syndrome.
Most of us are familiar with at least one genetic syndrome— Down syndrome is perhaps the most universally recognized, but there are actually thousands of them. They each involve multiple signs and symptoms that make a child very different from his peers, and their root cause is a quirk in their DNA—what was referred to in The Gene as “a misspelling.”
Despite lots of tests, we don’t yet know what “misspelling” is responsible for Joe’s condition. Although Joe’s result was inconclusive, it now joins a growing pool of data with others who have undergone similar testing. The result will grow to inform geneticists hoping to help families like ours, and may eventually reveal an answer for us too.
While this changing science has the promise to help solve the mystery of Joe’s condition, it also contains the potential for harm. As we saw in episode one, a nascent understanding of heredity led to the development of eugenics, which sought to prevent the birth of people whose physical and mental characteristics were deemed undesirable.
Virginia’s own Sterilization Act of 1924 asserted that “heredity plays an important part in the transmission of sanity, idiocy, imbecility, epilepsy and crime,” and resulted in the forced sterilization of more than 8,000 people. It was not officially ended until the mid-1970s, and has left the commonwealth with a shameful legacy and a considerable economic consequence.
While episode one focused largely on the history of genetics, episode two will cover its future in a similar light. We will see its promise in curing devastating illness, as well as its potential for disturbing pitfalls. We’ll meet a young woman undergoing a new gene therapy for a progressive neurological condition, and another whose cancer treatment is aided by close examination of DNA from her tumor.
But we’ll also see how this new “gene editing” power has the potential to slide back into the murky territory of eugenics. Will it be used only to alleviate suffering and enhance life, or will it be used to edit children like Joe right out of existence?
For better or worse, each of us is the result of the genes our parents gave us. Joe has my nose, his father’s eyes, and facial expressions that mirror those of his grandfathers. But the unexpected “misspelling” coiled up in his DNA has also given us a child we could never have imagined—and would never want to replace.
Watch episode two of The Gene: An Intimate History on VPM PBS on April 14 at 8:00 p.m. Episode one is available to stream here.
