Sickle Cell Disease: What It Is and Who It Affects
Sickle cell disease is a genetic red blood cell disorder. Normal red blood cells, which are round, move through small blood vessels to carry oxygen to all parts of the body. In someone who has sickle cell disease, the red blood cells become hard and are C-shaped like a sickle. The sickle cells die early, causing a constant shortage of red blood cells. The sickle cells also can get stuck and block blood flow, causing pain and other problems such as infections or strokes.
Other conditions people with sickle cell have include: hand-foot syndrome, swelling in the hands and feet that is usually the first symptom of the disease; anemia, which results in fatigue, irritability, rapid heart rate, difficulty breathing, jaundice, and delayed puberty; acute chest syndrome, which can be life-threatening and should be treated in a hospital; and vision loss, including blindness, which can occur when the blood vessels in the eye become blocked with sickle cells and the retina gets damaged. Some people also experience leg ulcers, malnutrition and growth retardation, gallstones, and a rare form of kidney cancer called renal medullary carcinoma.
The genetic disorder affects more than 4 million people and is most common among people of African, Hispanic, or Middle Eastern descent. Sickle cell disorder affects about 1 in 365 Black babies and 1 in 16,300 Hispanic babies, according to the Centers for Disease Control (CDC).
Children inherit sickle cell disease from their parents, with each contributing one sickle cell gene. A child who only inherits the sickle cell gene from one parent is healthy.
Because there is an increased risk of infection and other health problems in children with sickle cell disease, it’s important to get it diagnosed early. The disease is diagnosed with a blood test and is most often detected during routine newborn screening tests before the mother and child leave the hospital. Signs of sickle cell disease appear within a year of when a child is born.
The medical costs associated with the disease are an estimated $1 million for patients who reach 45 years of age. That translates to $10,000 a year for children and $30,000 annually for adults.
Available Treatments for Sickle Cell
Only a handful of drugs are approved to treat complications arising from sickle cell disease, including hydroxyurea and Endari, which can reduce the recurrance of sickle cell crisis in adults and children older than age 5. Last Fall, the US Food and Drug Administration approved Novartis AG’s Adakveo for sickle cell disease in patients 16 and older. While not a cure, the drug reduces the occurrences of sickle cell pain episodes by half. It costs between $85,000 and $113,000 a year, depending on dosing, but insured patients likely pay less than that.
According to the CDC, the only cure for sickle cell disease is a bone marrow or stem cell transplant, which takes healthy cells that form red blood cells from the donor and puts them into someone whose bone marrow is not working properly. But bone marrow and stem cell transplants can have serious side effects, including death.
Because sickle cell disease is caused by a gene mutation, gene editing therapies appear promising. Using RNA, GreenLight Biosciences is developing a gene therapy that ultimately could provide a cure to sickle cell disease.
After the gene therapy is approved, GreenLight Biosciences will accelerate the production of affordable treatments at scale.
“Manufacturing sufficient quantities of high-quality RNA at an accessible cost is critical for achieving the full potential of new therapies that aim to reach a global patient population,” Ortega-Valle said. “That capability does not yet exist in the market, but GreenLight’s end-to-end, self-contained manufacturing platform aims to make that possible for all RNA-based therapies and vaccines.”
About the Author
Margaret is an award-winning journalist who spent nearly 25 years in the newspaper industry. She has covered a variety of business topics, including residential and commercial real estate, technology, telecommunications, and cannabis.