Four years ago, Tom and Karen Hamilton received a devastating diagnosis. A doctor informed them that their nine-year-old daughter’s slight clumsiness—which they’d tried treating with physical and occupational therapy—was neurological, not physical. Specifically, Annie suffered from a rare, progressive, and currently incurable disorder known as Friedreich’s ataxia (FA).
Each cell in our bodies contains a sequence of DNA that is uniquely ours. This sequence is made up of four kinds of chemicals, known by the letters: A, C, G, and T.
Our genome—the complete set of our genes—comprises three billion of these letters. Thinking of our genome as this enormous set of letters is one way of understanding genetic mutations. Basically, mutations are misspellings. Just as misspelled words happen when a letter is swapped out for another, a genetic mutation occurs when one or more of the four letters aren’t where they should be.
When he was 19, Monkol Lek felt what it was like to be paralyzed.
A doctor had prescribed him a relaxant for his weak and aching muscles. The relaxant briefly rendered Lek immobile. “I remember lying there, not being able to move,” he recalled.