Co-inheritance of α-thalassemia among patients and controls.

Panel A displays a much higher prevalence of 3.7α-globin gene deletions among patients compared to unaffected controls [HbAA and HbSS combined (p = 0.003)]. This difference was mostly driven by a much lower proportion of 3.7 kb α-globin gene deletions among HbAA controls. Panel B displays the allele frequencies of the 3.7 kb α-globin gene deletions among patient and control. The frequencies were 22% among patients and 11.8% among controls (HbAS and HbAA combined) (p = 0.006). HbAS controls had more 3.7 kb α-globin gene deletions than HbAA controls (p = 0.02).