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Many children with sickle cell disease living in sub-Saharan Africa die before reaching age 5 years. We estimate the child mortality associated with sickle cell anaemia using an indirect approach to overcome the absence of systematic screening at birth.We did a retrospective, multicentre, case-control study in five countries in sub-Saharan Africa (Burkina Faso, Democratic Republic of the Congo, Côte d'Ivoire, Mali, and Senegal). Women with at least one child with a confirmed SS haemoglobin phenotype (sickle cell anaemia) and who had at least three (alive or deceased) children from the same father born more than 5 years ago were recruited at an outpatient consultation in a sickle cell disease care centre. Women who had children without sickle cell disease (control group) were recruited from the same area, with inclusion criteria of being a neighbour or relative of one of the mothers included in the study who had a child with sickle cell anaemia, having no child or other first-degree relative with major sickle cell syndrome, having at least three children (alive or deceased) born more than 5 years ago, and having a confirmed haemoglobin AA phenotype. During the mothers' interview, we collected data concerning the mortality of siblings from the same father of a child with sickle cell anaemia and characteristics of the family, such as age at the time of the survey and the level of education of both parents. Mortality rates were calculated for children younger than 1, 5, and 10 years using the Kaplan-Meier method after excluding the index children. We assumed, as per Mendel law, that in families who have a child with sickle cell anaemia and healthy heterozygous parents, 25% of children born on average have sickle cell anaemia. A multivariate Cox model was used to describe socioeconomic and geographical factors associated with mortality.Between Sept 1, 2017, and Nov 30, 2020, 1563 women who had at least one child with sickle cell anaemia and 4972 women from the same neighbourhood who had children without sickle cell disease were assessed for eligibility. Of 1563 women, 248 were excluded because the genotype of the index child was SC or S β-thalassaemia. 1315 families with cases of sickle cell anaemia and 1243 control families were included in the study. The median age of children (alive) was 14 years (IQR 8-20) in control families and 13 years (8-19) in families with cases of sickle cell anaemia. 5532 [50·6%] of 10 924 children were male. Mortality rates were 15·3% (95% CI 13·3-17·3) for children with sickle cell anaemia younger than 1 year, 36·4% (33·4-39·4) for those younger than 5 years, and 43·3% (39·3-47·3) for those younger than 10 years. Multivariate Cox survival analysis showed that belonging to a family with sickle cell anaemia (hazard ratio [HR] 2·23, 95% CI 1·96-2·54), living in the Democratic Republic of the Congo (HR 1·64, 1·34-2·01), having an older parent (father or mother age had similar effect; HR 1·12, 1·05-1·19 per 10 years of age), or a significantly higher global Multidimensional Poverty Index (HR 1·09, 1·03-1·14), independently increased the risk of mortality. Whereas, living in Senegal (HR 0·70, 95% CI 0·57-0·86) or having a mother with higher education (high school HR 0·66, 0·55-0·80 or advanced HR 0·41, 0·28-0·61) independently decreased the risk of mortality.Although higher than in high-income countries and affected by non-specific socioeconomic factors, the estimated mortality in children with sickle cell anaemia living in sub-Saharan African cities was substantially lower than previous estimates, suggesting an improvement of sickle cell anaemia care in this setting.Fondation Pierre Fabre.For the French translation of the abstract see Supplementary Materials section.

Oculocutaneous albinism type 2 (OCA2) is a pigmentation disorder characterized by hypopigmentation of the skin, hair and eyes and ocular features. Sickle cell disease (SCD) is caused either by homozygosity of the beta globin gene variant c.20A T/p.Glu6Val giving rise to severe anemia or by combined abnormal hemoglobins (HbS/βthal) leading to mild SCD. We report a 45 years old female patient from the Democratic Republic of Congo affected with these two disorders. She presented with creamy white skin and numerous pigmented patches called dendritic freckles, nystagmus, foveal hypoplasia grade 2, photophobia and very poor visual acuity. Sequencing of the OCA2 gene identified the common exon 7 deletion and a new pathogenic variant c.1444A C/p.Thr482Pro. She had mild SCD with a total Hb level of 101 g/l. Hbβ sequencing identified variants c.20A T giving rise to HbS and c.315 + 1 G A characteristic of β-thalassemia. A heterozygous 3.7 kb deletion of the α globin gene was also found. The combined Hbβ/α globin genotype explains the mild SCD phenotype. Co-occurrence of OCA2 and SCD raises the question whether the patient's phenotype simply results from the addition of the two diseases' phenotypes or whether interaction between the two diseases modulates the phenotype of each other.

Introduction: Many children with sickle cell anemia (SCA) require blood transfusions, which carry risks and utilize a scarce resource globally, particularly in Africa. Realizing Effectiveness Across Continents with Hydroxyurea (REACH, NCT01966731) has documented the safety, feasibility, and benefits of hydroxyurea for children with SCA living in sub-Saharan Africa. In REACH, hydroxyurea escalated to maximum tolerated dose (MTD) significantly decreased vaso-occlusive events, malaria, and death; transfusions were decreased by ~70% over 30 months of treatment when compared to the 2-month screening period. Characterizing how hydroxyurea reduces transfusion needs in REACH could contribute to improved clinical understanding and lead to better outcomes, a decreased transfusion burden, and preservation of the blood supply in these limited-resource settings. Methods: Transfusions were recorded prospectively in the REACH REDCap electronic database. Using time-varying predictors and landmark analysis, transfusions during screening and treatment were analyzed by clinical site, calendar month, age, gender, splenomegaly, hydroxyurea dose, MTD status, baseline and latest laboratory values (Hemoglobin, MCV, HbF, absolute neutrophil count, and platelets, all measured at least 30 days prior to the transfusion), alpha thalassemia trait, and G6PD deficiency. Incidence rate ratios (IRR) were calculated for treatment periods compared to screening. Univariate relationships were assessed using the Anderson-Gill model, plus multiple regression to estimate Hazard Ratios (HR) with 95% confidence intervals (CI's). Results: A total of 635 children with SCA enrolled in REACH, and 606 started hydroxyurea treatment. During screening, 48 transfusions were given to 43 children, and during the treatment phase 405 transfusions were administered to 214 children over an average treatment time of 5.2 ± 1.3 years. The transfusion rate was 43.3 per 100 patient-years during screening, which decreased to 22.0 per 100 patient-years during the initial fixed dose treatment period (IRR = 0.50; 95%CI = 0.35-0.74, p Conclusion: Hydroxyurea significantly reduces blood transfusion administration in children with SCA in sub-Saharan Africa, especially when escalated to MTD. Transfusions for the sole indication of anemia decreased significantly on hydroxyurea treatment, likely due to higher treatment-associated hemoglobin levels and decreased hemolysis, and transfusions for malaria also trended toward a decrease. Splenomegaly remains a risk factor for transfusions despite hydroxyurea treatment. Overall, increased access to and implementation of hydroxyurea treatment for children with SCA across sub-Saharan Africa may not only improve individual patient outcomes through reduction in anemia, transfusion burden, and transfusion-associated complications including infections, but may also to help preserve the scarce blood supply for the benefit of the larger population. Disclosures Aygun: Global Blood Therapeutics: Consultancy; Patient Centered Outcomes Research Institute: Research Funding; National Heart, Lung, Blood Institute: Research Funding; National Institute of Nursing Research: Research Funding; bluebird bio, Inc.: Membership on an entity's Board of Directors or advisory committees, Research Funding. Stuber: ASH Research Collaborative: Consultancy. Ware: Bristol Myers Squibb: Research Funding; Addmedica: Research Funding; Hemex Health: Research Funding; Nova Laboratories: Research Funding; Novartis: Other: DSMB Chair; Editas: Other: DSMB Chair.