Prospective Newborn Screening for Sickle Cell Disease and Other Inherited Blood Disorders in Central Malawi

Abstract

Objectives: Newborn screening in the United States and Europe allows early identification of congenital disorders but does not yet exist in most low-resource settings, especially in sub-Saharan Africa. Newborn screening can identify multiple inherited hematological disorders, but feasibility and effectiveness for Africa are not fully determined. Methods: Surplus dried blood spot collected in Central Malawi through the HIV Early Infant Diagnosis surveillance program were repurposed and tested by isoelectric focusing for sickle cell disease and trait. Additional genetic testing identified G6PD deficiency and alpha thalassemia. Results: Testing of 10,529 cards revealed an overall sickle cell trait prevalence of 7.0% (range 3.9-9.7% by district); 10 of 14 infants identified with sickle cell disease (prevalence 0.1%) were located and received care at a specialized clinic. Subsequent testing of 1,329 randomly selected cards identified alpha thalassemia trait in 45.7% of samples, and G6PD deficiency in 20.4% of males and 3.4% of females, with 29.0% of females as heterozygous carriers. Conclusion: Inherited hematological disorders are common in Central Malawi; early identification through newborn screening can improve clinical outcomes and should be supported throughout Africa.

Keywords: G6PD deficiency; Malawi; alpha thalassemia; newborn screening; sickle cell disease; sickle cell trait.

FIGURE 1

Malawi Sickle Surveillance Study prevalence estimates for sickle cell trait, historical malaria, α-thalassemia trait (-α/-α or -α/αα), G6PD deficiency in males, and G6PD deficiency/carrier status in females by district in the Central region of Malawi, 2018. Historical malaria prevalence estimates, (Plasmodium falciparum in children ages 1–10) are taken from data from 1970 to 2001 at 73 survey locations across Malawi [18]. Stars represent the location of Early Infant Diagnosis laboratory collaborators (Partners in Hope and Kamuzu Central Hospital in Lilongwe and Mzimba District Hospital in the North).