title: Coinheritance of α-thalassemia decreases the risk of cerebrovascular disease in a cohort of children with sickle cell anemia.
abstract: The study estimated α-thalassemia (α-thal) prevalence and assessed its associations with clinical and hematological features in a random sample of Brazilian children with sickle cell anemia (208 Hb SS and 13 Hb S-β⁰-thal). α-Thalassemia genotyping was carried out by multiplex polymerase chain reaction (m-PCR) for seven alleles. Clinical and hematological data were retrieved from the 221 children's medical files. Their ages ranged from 2.5 to 10.4 years. Of the Hb SS children, 27.9% carried -α(3.7)/αα and 1.4% -α(3.7)/-α(3.7). The presence of α-thal was significantly associated with reduction in MCV, MCH, WBC values and reticulocyte counts. No significant association with blood transfusion or acute chest syndrome (ACS), was found. α-Thalassemia genotypes were strongly associated with reduction in risk for cerebrovascular disease (CVD) (conditional and abnormal transcranial Doppler or stroke; p = 0.007). The interaction of α-thal with other modulating factors should be investigated in order to define subphenotypes of the disease and to use them as clinical tools in the follow-up care of patients.
authors.affiliation: Fundação Centro de Hematologia e Hemoterapia deMinas Gerais (HEMOMINAS Foundation), Belo Horizonte, Brazil.
authors.forename: André Rolim
authors.initials: AR
authors.lastname: Belisário
authors.forename: Cibele Velloso
authors.initials: CV
authors.lastname: Rodrigues
authors.forename: Marina Lobato
authors.initials: ML
authors.lastname: Martins
authors.forename: Célia Maria
authors.initials: CM
authors.lastname: Silva
authors.forename: Marcos Borato
authors.initials: MB
authors.lastname: Viana
mesh_terms: D000293:Adolescent; D000483:Alleles; D000704:Analysis of Variance; D000755:Anemia, Sickle Cell / Q000150:complications / Q000235:genetics*; D001938:Brazil / Q000453:epidemiology; D002561:Cerebrovascular Disorders / Q000150:complications / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004252:DNA Mutational Analysis; D005787:Gene Frequency; D005838:Genotype; D006451:Hemoglobin, Sickle / Q000235:genetics; D006801:Humans; D016133:Polymerase Chain Reaction; D015995:Prevalence; D018570:Risk Assessment; D012307:Risk Factors; D055542:alpha-Globins / Q000235:genetics; D017085:alpha-Thalassemia / Q000150:complications / Q000453:epidemiology / Q000235:genetics*
chemical_list: D006451:Hemoglobin, Sickle; D055542:alpha-Globins