"I saved the most interesting case for last," said Molly Wilson, the resident who'd been on call the night before. It was a Saturday morning in early February. Molly and I had spent the last hour touring the Infants' Unit with the interns, stopping to discuss and examine each child who was unlucky enough to be inhabiting the unit that day. I was tired, the day was cold and gray outside, and I'd much rather have been at home in bed. But as the attending physician that month, the most senior doctor on the service, it was my job to make sure these children got the best care possible, and so fighting off the urge to daydream, I focused my attention on the resident. "This baby's name is Jarret Fox," Molly continued. "He's a three-month-old who was admitted last night for dehydration. According to his mother, Jarret stopped eating four days ago."
"Stopped eating?" I repeated, quickly coming to full attention. "What do you mean he stopped eating?"
"Just that," Molly replied. "His mom says that Jarret was happy and healthy a week ago. Then, on Tuesday, he seemed to lose interest in nursing. He just stopped sucking, his mother says, and he hasn't eaten anything since."
"That can't be right," I responded. "Three-month-olds don't just suddenly stop nursing and starve themselves until they get dehydrated."
"Well, I didn't believe it either at first, but the mother keeps telling the same story: she's been trying to force-feed him since Wednesday but hasn't had any success. Yesterday she brought him to her pediatrician. He said Jarret was about 5 percent dehydrated. He also said the kid was much floppier than he'd been the last time he'd seen him. So he sent him in for rehydration and a full evaluation."
That last part of Molly's report, the part about the increased floppiness, made my heart sink. It suggested a condition I hoped this baby didn't have. "Do you have any ideas about a diagnosis?" I asked.
"The only thing I can think of is spinal muscular atrophy," Molly said.
"That's what I'm thinking, too," I replied. "I hope we're wrong. Let's go see him."
Put simply, a diagnosis of the infantile form of SMA is a death sentence. A relatively rare inherited disease in which the nerves that control movement mysteriously degenerate and disappear, it is the childhood equivalent of the better-known (but no better understood) amyotrophic lateral sclerosis. As the nerves vanish during the first months of life, a child with SMA grows progressively weaker. After initial problems with feeding, the infant loses the ability to move its arms and legs. Breathing also becomes difficult. With time, the child becomes more and more hungry for air until finally, by about the first birthday, he or she dies. The cause is usually pneumonia, a common infection in lungs that aren't getting enough air.
As a medical geneticist, I have had the unenviable task of helplessly watching more than a dozen patients live out the nightmarish symptoms of SMA. The only thing I could do was aid families in coping with the loss of their children. As I entered Jarret Fox's hospital room that Saturday morning, the faces of all these children and their families flashed through my mind.
"Ms. Fox," Molly said as we approached Jarret's crib, "this is Dr. Marion. He's our attending pediatrician."
"Sorry we have to meet under these circumstances," I said with a smile as I shook her hand. Barefoot, clad in a peasant blouse and bell-bottom jeans, her long, straight hair parted down the middle, Jarret's mom looked like a long-lost refugee from the Summer of Love. She also looked as if she could use a good night's sleep. "How are you doing?"
"Not too well," she replied. "I'm hoping someone will be able to tell me what's wrong with my son."
"We're going to try to get to the bottom of it," I said. "First, maybe you can tell me the story from the beginning."
Without hesitation, Ms. Fox spilled out the short tale of her son's life. After an uncomplicated pregnancy, Jarret had been born at his parents' home in North Salem, a rural town north of New York City. He was the couple's second child: their daughter, Jessica, now three years old, was "healthy as a horse." Although his birth was attended only by a midwife, Jarret was examined on the first day of life by the family's pediatrician (the only one in the area who practiced homeopathic medicine and made house calls) and declared to be in excellent health. His mother could think of nothing unusual about her son's newborn period: in her words, he had been "like my other baby."
The infant had been seen by the pediatrician on a regular schedule, first at two weeks, then at a month, then at two months. He'd received his immunizations and had been growing and developing normally. Ms. Fox explained that her family were strict vegetarians who ate only whole, natural foods. She assured me that Jarret had had nothing but breast milk, adding proudly, "My daughter was exclusively breast-fed for the first 18 months of her life."
But four days ago this idyllic existence had ended. Jarret had simply refused to nurse. "He just wouldn't latch onto my breast," she said sadly. "Nothing I did got him interested. It was like a switch had been turned off in his brain and he wouldn't do it anymore. Just like that."
"Has he been hungry?" I asked, less certain now about the diagnosis.
"At first he was," she said. "That first day, he cried and cried. It was pathetic. But since then, he's just been lifeless, like he just doesn't care anymore."
I could see what Ms. Fox meant. Jarret was a sturdy, beautiful baby, but he lay as limp as a rag doll in his hospital crib, an IV in his left arm and a feeding tube in his left nostril. Although his eyes returned my gaze, Jarret seemed passive and expressionless.
"This doesn't sound like SMA," I said, shaking my head. After finishing my examination, I thanked Ms. Fox and told her that we needed to speak with the neurologist and that we'd be back later. Molly, a few interns, and I assembled in the corridor.
"SMA doesn't start suddenly like this," I began. "The weakness comes on gradually—the first day, the parents notice that the kid's a little floppy, the next day he's a bit more floppy, then a little more floppy the next, until finally they find they can't get him to eat enough to keep himself going. That's when the kid comes to the hospital with dehydration and the diagnosis is made. But this story of the weakness coming on suddenly like a switch going off—that's too acute to be SMA!"
"I agree," Molly said. "It sounds almost like the kid was poisoned."
