Association of alpha‐thalassemia and Glucose‐6‐Phosphate Dehydrogenase deficiency with transcranial Doppler ultrasonography in Nigerian children with sickle cell anemia

• Published in: Journal of clinical laboratory analysis 2021-06, Vol.35 (6), p.e23802-n/a
• Main Authors: Ojewunmi, Oyesola Oyewole, Adeyemo, Titilope Adenike, Oyetunji, Ajoke Idayat, Benn, Yewande, Ekpo, Mfoniso Godwin, Iwalokun, Bamidele Abiodun
• Format: Article
• Language: English
• Subjects: alpha‐thalassemia; Anemia; Blood diseases; Blood flow; Blood transfusions; Cerebral blood flow; Children; Dehydrogenases; Doppler effect; Gene deletion; Glucose; Glucosephosphate dehydrogenase; glucose‐6‐phosphate dehydrogenase deficiency; Hemoglobin; Laboratories; Polymerase chain reaction; Restriction fragment length polymorphism; Sickle cell anemia; Sickle cell disease; Stroke; Thalassemia; transcranial Doppler ultrasonography; Ultrasound; Velocity
• ISSN: 0887-8013; 1098-2825
• DOI: 10.1002/jcla.23802

Background Stroke is a devastating complication of sickle cell anemia (SCA) and can be predicted through abnormally high cerebral blood flow velocity using transcranial Doppler Ultrasonography (TCD). The evidence on the role of alpha‐thalassemia and glucose‐6‐phosphate dehydrogenase (G6PD) deficiency in the development of stroke in children with SCA is conflicting. Thus, this study investigated the association of alpha‐thalassemia and G6PD(A−) variant with abnormal TCD velocities among Nigerian children with SCA. Methods One hundred and forty‐one children with SCA were recruited: 72 children presented with normal TCD (defined as the time‐averaged mean of the maximum velocity:  A and 376A > G) were genotyped using restriction fragment length polymorphism—polymerase chain reaction. Results The frequency of α‐thalassemia trait in the children with normal TCD was higher than those with abnormal TCD: 38/72 (52.8%) [α‐/ α α: 41.7%, α ‐/ α ‐: 11.1%] versus 21/69 (30.4%) [α‐/ α α: 27.5%, α ‐/ α ‐: 2.9%], and the odds of abnormal TCD were reduced in the presence of the α‐thalassemia trait [Odds Ratio: 0.39, 95% confidence interval: 0.20–0.78, p = 0.007]. However, the frequencies of G6PDA− variant in children with abnormal and normal TCD were similar (11.6% vs. 15.3%, p = 0.522). Conclusion Our study reveals the protective role of α‐thalassemia against the risk of abnormal TCD in Nigerian children with SCA. We investigated the association of alpha‐thalassemia deletion and G6PD deficiency [G6PDA‐] with stroke risk as stratified by TCD velocity status among Nigerian children with sickle cell anemia. Our results show that absence of α‐thalassemia increased risk of abnormal TCD and remains an independent predictor of abnormal TCD alongside lower hemoglobin oxygen saturation.