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Importance: Sickle cell trait (SCT), defined as the presence of 1 hemoglobin beta sickle allele (rs334-T) and 1 normal beta allele, is prevalent in millions of people in the US, particularly in individuals of African and Hispanic ancestry. However, the association of SCT with COVID-19 is unclear., Objective: To assess the association of SCT with the prepandemic health conditions in participants of the Million Veteran Program (MVP) and to assess the severity and sequelae of COVID-19., Design, Setting, and Participants: COVID-19 clinical data include 2729 persons with SCT, of whom 353 had COVID-19, and 129 848 SCT-negative individuals, of whom 13 488 had COVID-19. Associations between SCT and COVID-19 outcomes were examined using firth regression. Analyses were performed by ancestry and adjusted for sex, age, age squared, and ancestral principal components to account for population stratification. Data for the study were collected between March 2020 and February 2021., Exposures: The hemoglobin beta S (HbS) allele (rs334-T)., Main Outcomes and Measures: This study evaluated 4 COVID-19 outcomes derived from the World Health Organization severity scale and phenotypes derived from International Classification of Diseases codes in the electronic health records., Results: Of the 132 577 MVP participants with COVID-19 data, mean (SD) age at the index date was 64.8 (13.1) years. Sickle cell trait was present in 7.8% of individuals of African ancestry and associated with a history of chronic kidney disease, diabetic kidney disease, hypertensive kidney disease, pulmonary embolism, and cerebrovascular disease. Among the 4 clinical outcomes of COVID-19, SCT was associated with an increased COVID-19 mortality in individuals of African ancestry (n = 3749; odds ratio, 1.77; 95% CI, 1.13 to 2.77; P = .01). In the 60 days following COVID-19, SCT was associated with an increased incidence of acute kidney failure. A counterfactual mediation framework estimated that on average, 20.7% (95% CI, -3.8% to 56.0%) of the total effect of SCT on COVID-19 fatalities was due to acute kidney failure., Conclusions and Relevance: In this genetic association study, SCT was associated with preexisting kidney comorbidities, increased COVID-19 mortality, and kidney morbidity.

Importance: African Americans and individuals of African ancestry have a higher risk of stroke compared with non-Hispanic white individuals. Identifying the source of this disparity could provide an opportunity for clinical stroke risk stratification and more targeted therapy. Whether sickle cell trait (SCT) is an indicator of increased risk of ischemic stroke among African Americans is still unclear., Objective: To examine whether SCT is associated with a higher risk of incident ischemic stroke among African Americans., Design, Setting, and Participants: This meta-analysis assessed the association of SCT with the risk of incident ischemic stroke. Four large, prospective, population-based studies with African American cohorts were assessed: Jackson Heart Study (September 1, 2005, through December 31, 2012), Multi-Ethnic Study of Atherosclerosis (July 1, 2002, through December 31, 2012), Reasons for Geographic and Racial Differences in Stroke (January 1, 2003, through December 31, 2014), and Women's Health Initiative (October 1, 1998, through December 31, 2012). Using a Cox proportional hazards regression model adjusted for major stroke risk factors, this study estimated the hazard ratio for incident ischemic stroke associated with SCT. Data analysis was performed from July 10, 2016, to February 2, 2017., Interventions or Exposures: Participants' SCT status determined by polymerase chain reaction assay genotyping or a combination of whole-exome sequencing and imputation., Main Outcomes and Measures: Incident ischemic stroke., Results: This meta-analysis included 19 464 African American individuals (1520 with SCT, 17 944 without SCT, and 620 with ischemic stroke) from 4 studies, with a mean (SD) age of 60.0 (13.0) years (5257 [27.0%] men and 14 207 [73.0%] women). No differences were found in the distribution of risk factors for ischemic stroke comparing participants with and those without SCT at study visit 1 in each cohort. The crude incidence of ischemic stroke was 2.9 per 1000 person-years (95% CI, 2.2-4.0 per 1000 person-years) among those with SCT and 3.2 per 1000 person-years (95% CI, 2.7-3.8 per 1000 person-years) among those without SCT. After stroke risk factors were adjusted for, the hazard ratio of incident ischemic stroke independently associated with SCT in the meta-analysis of all 4 cohorts was 0.80 (95% CI, 0.47-1.35; P = .82). The results of the meta-analysis were similar to those of individual cohorts, in which the results were also similar., Conclusions and Relevance: Sickle cell trait may not be associated with incidence of ischemic stroke among African Americans. The results of this study suggest performing a more thorough clinical evaluation of a stroke patient with SCT rather than assuming that SCT is the etiologic factor for the stroke.

Histochemical and light and electron microscopic studies of two eyes of a patient with homozygous sickle cell disease and angioid streaks demonstrated heavy calcification and breaks in Bruch's membrane. We were unable to demonstrate iron deposition by histochemical techniques or transmission electron microscopy. These studies suggest that calcification rather than iron deposition is the major factor leading to brittleness of Bruch's membrane in patients with hemolytic anemia and angioid streaks.

Two siblings assumed on the basis of clinical and hematological evidence to have homozygous sickle cell (SS) disease were found to have a mother without sickle hemoglobin. Subsequent investigation and hemoglobin structural studies indicated the diagnosis to be sickle cell-Hb Lepore Boston syndrome. This syndrome generally manifests clinically significant sickle cell disease, and this genotype should be borne in mind in apparent SS disease where a parent without sickle hemoglobin in discovered.

A prospective study was carried out to discern the outcome of pregnancy and distribution of birth weights of infants delivered of 85 women with sickle cell trait (AS) compared with a control group of 85 women with normal hemoglobin (AA) who were matched for race, age, parity, and sex of offspring. The distribution of birth weight of offspring of primiparous and multiparous women and the proportion of low-birth-weight infants did not differ significantly between infants born to mothers with AS and those in the control group. Similarly, there was no statistically significant difference between the birth weight of infants born to primipara or multipara. Also, the overall incidence of complications among women with AS did not differ from the incidence in the control group. The findings do not support previous reports that there may be definable pathologic correlates of childbearing in women with AS.

Recent mass screening programs for sickle cell trait have been the first large-scale efforts to detect potentially deleterious genes and to provide genetic counseling to healthy carriers. In these programs, the expected prevalence of sickle hemoglobin and hemoglobin C has been found, and other mutant hemoglobin genes have also been uncovered. Many of these are not associated with disease, but simply reflect normal genetic diversity. A paradox of this finding is illustrated when, in counseling, many persons demonstrate difficulty in understanding that though they have an abnormal hemoglobin gene, they themselves are not ill or abnormal. The problem's solution lies in educating both health professionals and the public so that the normal existence of considerable genetic diversity is recognized. Since every person may carry mutant genes, whether potentially deleterious or innocuous, our definition of normal must be revised.