BOSTON: Helen Obando, a shy slip of a girl, lay in a hospital bed in June waiting for a bag of stem cells from her bone marrow , modified by gene therapy , to start dripping into her chest. The hope was that the treatment would cure her of sickle cell disease, an inherited blood disorder that can cause excruciating pain, organ damage and early death.
Helen, who at 16 was the youngest person ever to undergo the therapy, was sound asleep for the critical moment. For more than a halfcentury, scientists have known the cause of sickle cell disease: A single mutation in a gene turns red blood cells into rigid crescent or sickle shapes instead of soft discs. These misshapen cells get stuck in veins and arteries, blocking the flow of blood that carries oxygen to the body and causing the disease’s horrifying hallmark: episodes of agony that begin in babyhood.
Researchers have worked for decades on finding a cure, but experts said the effort has been hindered by chronic underfunding, in part because most of the estimated 100,000 people in the United States who have the disease are African Americans, often poor or of modest means.
This is the story of two quests for a sickle cell cure — one by the Obando family and one by a determined scientist at Boston Children’s Hospital, Dr Stuart Orkin, 73, who has labored against the disease since he was a medical resident in the 1970s.
Scientists have been experimenting with gene therapy for two decades. And it will be years before they know if this new procedure, which aims to flip a genetic switch so the body produces healthy blood, is effective in the long term. But if it is, sickle cell disease could be the first common genetic disorder to be cured by manipulating human DNA .
Blood cells filled with fetal hemoglobin do not sickle.
The trial — run by Dr David Williams, an expert in the biology of blood-forming stem cells, and Esrick — has a straightforward goal: “We’re going to make the blood cells think they are still in the fetus,” Williams said. In the months after the gene therapy infusion, Helen’s symptoms have disappeared. She had no signs of sickle cell disease.