"Everyone has an issue they're dealing with," said Harriett, a homemaker and devout Baptist. "This is yours. The question is, how will you deal with it?" Both told him to trust God.

They fetched his school assignments and made sure he kept up when he was out sick. He became a straight-A student.

When he was 13, a doctor in yet another emergency room asked what he wanted to be when he grew up. Carlton wasn't sure, but he did know that many comic-book superheroes were born of physics accidents.

"A physicist," he said.

"Well, you already know more about sickle-cell than I do," the doctor replied. "What about medicine?"

Years later, Haywood narrows his eyes at the memory

"Isn't it interesting," he says, "how a well-timed question can change the way you view what you might be able to do?"

Disparities

Sickle-cell overwhelmingly affects the urban poor, a demographic that suffers disproportionately from social instability, many studies show.

That means, among other things, that they often lack support when crises come.

As Haywood grew older, he realized he'd never had to drop out of school as so many with sickle-cell do. He'd never had the disabling strokes that ruin school careers and wipe out futures by the thousands. His grades got him into the University of Virginia, where his plan was to pursue a career in medicine.

Harriett had always told him God gave him sickle-cell for a reason. The idea used to make him angry. Now he wondered whether she had a point.

The attacks never went away — the day before his freshman year began, he suffered his worst crisis ever, causing him to miss a semester — but once he enrolled, even failure seemed to give him direction.

Early that first year, for instance, when he realized he disliked working in laboratories, an adviser suggested a subject he'd never heard of.

"Intro to Bioethics changed my life," Haywood says. "I loved reading about ethical dilemmas in medicine. It presented a whole new way of asking questions."

He earned a master's degree in bioethics from Virginia and his doctorate in public health from Hopkins. Along the way, he saw as few others could that sickle-cell, a disease at the molecular level, radiates into the world.

Take socioeconomics. Most patients, he learned, receive government medical assistance, which means their health care providers are undercompensated. This discourages others from going into the field, one reason so few primary-care physicians know the rudiments of sickle-cell.

That problem reinforces another: lacking knowledge, health care providers are less likely to empathize with the patients' unique needs, causing poorer treatment and more stress.

Worse, he found, funding for sickle-cell research is abysmal. In 2004, Haywood came across a federally supported study that compared how well the U.S. funds research into two comparable genetic disorders: sickle-cell disease and cystic fibrosis. The results shocked him.

In 2003, it turned out, sickle-cell disease attracted about $500,000 in private charitable funding. Cystic fibrosis, which affected fewer than a third as many people (nearly all of them Caucasian) attracted $150 million — 300 times as much.