title: Heme oxygenase-1 gene promoter polymorphism is associated with reduced incidence of acute chest syndrome among children with sickle cell disease.
abstract: Sickle cell disease is a common hemolytic disorder with a broad range of complications, including vaso-occlusive episodes, acute chest syndrome (ACS), pain, and stroke. Heme oxygenase-1 (gene HMOX1; protein HO-1) is the inducible, rate-limiting enzyme in the catabolism of heme and might attenuate the severity of outcomes from vaso-occlusive and hemolytic crises. A (GT)(n) dinucleotide repeat located in the promoter region of the HMOX1 gene is highly polymorphic, with long repeat lengths linked to decreased activity and inducibility. We examined this polymorphism to test the hypothesis that short alleles are associated with a decreased risk of adverse outcomes (hospitalization for pain or ACS) among a cohort of 942 children with sickle cell disease. Allele lengths varied from 13 to 45 repeats and showed a trimodal distribution. Compared with children with longer allele lengths, children with 2 shorter alleles (4%; ≤ 25 repeats) had lower rates of hospitalization for ACS (incidence rate ratio 0.28, 95% confidence interval, 0.10-0.81), after adjusting for sex, age, asthma, percentage of fetal hemoglobin, and α-globin gene deletion. No relationship was identified between allele lengths and pain rate. We provide evidence that genetic variation in HMOX1 is associated with decreased rates of hospitalization for ACS, but not pain. This study is registered at www.clinicaltrials.gov as #NCT00072761.
authors.affiliation: Clinical and Molecular Hemostasis Laboratory Branch, Division of Blood Disorders, National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, GA, USA.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Bean
authors.forename: Sheree L
authors.initials: SL
authors.lastname: Boulet
authors.forename: Dorothy
authors.initials: D
authors.lastname: Ellingsen
authors.forename: Meredith E
authors.initials: ME
authors.lastname: Pyle
authors.forename: Emily A
authors.initials: EA
authors.lastname: Barron-Casella
authors.forename: James F
authors.initials: JF
authors.lastname: Casella
authors.forename: Amanda B
authors.initials: AB
authors.lastname: Payne
authors.forename: Jennifer
authors.initials: J
authors.lastname: Driggers
authors.forename: Heidi A
authors.initials: HA
authors.lastname: Trau
authors.forename: Genyan
authors.initials: G
authors.lastname: Yang
authors.forename: Kimberly
authors.initials: K
authors.lastname: Jones
authors.forename: Solomon F
authors.initials: SF
authors.lastname: Ofori-Acquah
authors.forename: W Craig
authors.initials: WC
authors.lastname: Hooper
authors.forename: Michael R
authors.initials: MR
authors.lastname: DeBaun
mesh_terms: D056586:Acute Chest Syndrome / Q000453:epidemiology / Q000209:etiology / Q000235:genetics*; D000293:Adolescent; D000755:Anemia, Sickle Cell / Q000150:complications / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D018900:Dinucleotide Repeats; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D051547:Heme Oxygenase-1 / Q000235:genetics*; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D008297:Male; D060885:Multiplex Polymerase Chain Reaction; D010146:Pain / Q000453:epidemiology / Q000235:genetics; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic / Q000235:genetics*
chemical_list: C496541:HMOX1 protein, human; D051547:Heme Oxygenase-1