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Updated chapter to come.
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Individuals are diagnosed with sickle cell disease (SCD) if they have one of several genotypes that result in at least half of their hemoglobin (Hgb) being Hgb S. Sickle cell anemia (SCA) refers to the condition associated with homozygosity for the Hgb S mutation (Hgb SS). Other Hgb mutations may occur with Hgb S causing a similar but milder condition. In SCA, the presence of intracellular hemoglobin S polymerization leads to chronic hemolytic anemia, vasoocclusive crises of varying severity and frequency with cumulative organ damage and systemic manifestations that include impairment in growth and development, susceptibility to infection, and reduced quality and duration of life
Segal JB et al. Hydroxyurea for the Treatment of Sickle Cell Disease. Rockville, MD: Agency for Healthcare Research and Quality, 2008 Feb. Report No. 08-E007
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Epidemiology
Platt OS et al. N Engl J Med 1994;330:1639–1644 (3764 patients. followed to determine life expectancy)
Sickle Cell Research for Treatment and Cure. Bethesda, MD: NIH Publication No. 02-5214;2002:1–16
Dept. of Energy, Human Genome Project. www.nhlbi.nih.gov/resources/docs/scd30/scd30.pdf [accessed August 5, 2013]
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Major Sickle Hemoglobinopathies: Laboratory Features