Sickle cell disease

About sickle cell disease

Sickle cell disease (SCD) is a lifelong inherited blood disorder that impacts hemoglobin, a protein carried by red blood cells (RBCs) that delivers oxygen to tissues and organs throughout the body. Due to a genetic mutation, people with SCD form abnormal hemoglobin known as sickle hemoglobin.1 Through a process called hemoglobin polymerization, RBCs become sickled – deoxygenated, crescent-shaped and rigid. The sickling process causes hemolytic anemia (low hemoglobin due to RBC destruction2) and blockages in capillaries and small blood vessels, which impede the flow of blood and oxygen throughout the body. The diminished oxygen delivery to tissues and organs can lead to life-threatening complications, including stroke and irreversible organ damage.3-5 Chronic organ damage is the leading cause of death in adults with SCD.6

SCD patient population

SCD affects an estimated 100,000 people in the United States,7 including approximately 86,000 of whom are 12 years of age and older.8 The majority of those affected by SCD in the United States are African Americans and Hispanic Americans. About 90% of people with SCD are African American or of African descent.9 About 1 in 500 African Americans9 and 1 in 1,000 to 1,400 Hispanic Americans is born with the genetic defect that causes SCD.10

SCD affects millions of people throughout the world, particularly among those whose ancestors are from sub-Saharan Africa. It also affects people of Hispanic, South Asian, Southern European and Middle Eastern ancestry.11

Personal and socioeconomic impact of SCD

SCD is an expensive problem that places a major burden on patients and society. Healthcare costs can be as high as $286,000 a year for an SCD patient with complications such as stroke.12 Beyond the physical effects of the disease – including inflammation, multi-organ damage and early death – there are significant emotional and socioeconomic impacts on SCD patients and their families. Many suffer financial hardships, and their lifetime earnings potential is drastically lower than that of individuals without SCD,13 with a recent study estimating approximately $700,000 in lost lifetime income per patient.14

For children with SCD, the symptoms and necessary hospitalizations can significantly impact their ability to consistently attend school, meaning they often fall behind. For caregivers, providing at-home care affects their productivity and often creates a devastating financial burden for the family. Additionally, people living with SCD face significant misconceptions and stigmas, which can further exacerbate the challenges posed by living with this disease.

Barriers to care

Despite the seriousness of SCD and the potentially devastating outcomes, many patients do not have access to the care they need. Because the disease affects so many different organs, people with SCD need to regularly see a primary care physician and/or hematologist to obtain a referral to specialists. However, most SCD patients do not have a primary care doctor, and only about 1 in 5 is seen by a hematologist in an average year.15

  1. Piel et al. N Engl J Med. 2017;376:1561-1573
  2. Stuart and Nagel. Lancet. 2004;364:1343.
  3. Piel et al. N Engl J Med. 2017. 376:1561-1573
  4. Kato GJ, et al. J Clin Invest. 2017;127(3):750-760.
  5. Caboot JB, Allen JL. Paediatr Respir Rev. 2014;15(1):17-23.
  6. Powars, DR et al. Medicine. 2005;84:363-–376.
  7. Centers for Disease Control and Prevention website. Sickle Cell Disease (SCD). https://www.cdc.gov/ncbddd/sicklecell/data.html.
  8. Data on file.
  9. Genetics Home Reference. Sickle Cell Disease. https://ghr.nlm.nih.gov/condition/sickle-cell-disease#statistics.
  10. Genetics Home Reference. Sickle Cell Disease. https://ghr.nlm.nih.gov/condition/sickle-cell-disease#statistics.
  11. Centers for Disease Control and Prevention website. Sickle Cell Disease (SCD). https://www.cdc.gov/ncbddd/sicklecell/data.html.
  12. Song, X, et al. 2019 American Society of Hematology Annual Meeting. Poster #3388.
  13. Agodoa, I. et al. 2018 American Society of Hematology Annual Meeting. Abstract #119420.
  14. Agodoa, I. et al. 2018 American Society of Hematology Annual Meeting. Abstract #119420.
  15. Dampier et al. 2017 American Society of Hematology Annual Meeting. Abstract# 4660.