Approximately how many sickle cell anemia births occur annually worldwide, and what percentage are of African descent?

Approximately how many sickle cell anemia births occur annually worldwide, and what percentage are of African descent?

• A. 300,000 births; 90% African descent
• B. 100,000 births; 50% African descent
• C. 600,000 births; 20% African descent
• D. 50,000 births; 5% African descent

Answer: (A)

The question tests the global burden of sickle cell disease at birth and how it’s distributed among populations. The best answer reflects the widely cited estimate that about 300,000 babies are born each year with sickle cell disease worldwide, and roughly nine in ten of these births occur in populations of African descent. This pattern comes from the high frequency of the HbS allele in sub-Saharan Africa, a region where malaria exerted strong selective pressure for the trait, leading to many carriers and, consequently, many affected births in that population. The other options either understate the global number or mischaracterize the geographic/ethnic distribution, making them less consistent with the global epidemiology.

The question tests the global burden of sickle cell disease at birth and how it’s distributed among populations. The best answer reflects the widely cited estimate that about 300,000 babies are born each year with sickle cell disease worldwide, and roughly nine in ten of these births occur in populations of African descent. This pattern comes from the high frequency of the HbS allele in sub-Saharan Africa, a region where malaria exerted strong selective pressure for the trait, leading to many carriers and, consequently, many affected births in that population. The other options either understate the global number or mischaracterize the geographic/ethnic distribution, making them less consistent with the global epidemiology.