@Scudellari
DOMINIC GESSLER lifts two squirming mice from their cages. Sherri Epstein flinches, but Gessler coaxes her to hold out her hands. He places the small animals in her palms, and they skitter in tiny circles, tickling her skin. “Now,” says Gessler. “Which one used to have Canavan disease?”
A few miles away, at Epstein’s home in Worcester, Massachusetts, a young woman lies in bed, her thin limbs bent and still, her curly red hair splayed across a pillow. This is Rachel, Epstein’s 17-year-old daughter, born with Canavan disease—a debilitating, fatal brain disorder. As a newborn, Rachel opened her mouth as if to scream but made no sound. As an infant, she never moved in her sleep. When Rachel failed to lift her head by six months of age, an early intervention therapist suspected she had cerebral palsy. Epstein wishes it had been so. Instead, Rachel had inherited a mutated version of a gene called ASPA from each of her parents. Without a healthy copy of that gene, her cells could not produce a protein needed to break down acid in the brain. So the acid built up, then slowly ate away at the insulation protecting Rachel’s neurons, turning her white matter into a sponge pocketed with fluid-filled sacs. As a result, Rachel does not talk; she cannot see or control her limbs or other bodily functions; she has seizures and will likely not live to adulthood.