title: Phenotypic effect of α-globin gene numbers on Indian sickle β-thalassemia patients.
abstract: BACKGROUND
  Sickle cell β-thalassemia is a compound heterozygous state of β-thalassemia and sickle cell anemia. Patient with these conditions showed mild-to-severe clinical phenotype.
  
  
  OBJECTIVE
  The objective of this study was to evaluate the effects of α-globin gene numbers on the phenotype of sickle cell β-thalassemia patients.
  
  
  METHODS
  Seventy-five sickle cell β-thalassemia patients were characterized. Clinical, hematological, and molecular characterization was performed in all subjects. Amplified refectory mutation system-polymerase chain reaction was applied for β-thalassemia mutation study while α-genotyping was conducted by Gap-PCR.
  
  
  RESULTS
  Highest frequency of IVS1-5 (33 out of 75 patients) β-thalassemia genotype was recorded. Twenty-eight patients were reported with α-globin chain deletion while four had α-triplications (Anti α-3.7kb). Sickle β-thalassemia patients with α-chain deletions ameliorate hematological and clinical variables.
  
  
  CONCLUSIONS
  This study indicates that the coexistence of α-globin chain deletions showed mild phenotype instead of absence of α-chain deletions while the patients with triplication of α-genes express severe phenotype.
authors.affiliation: Department of Hematology, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Sanjay Kumar
authors.initials: SK
authors.lastname: Pandey
authors.forename: Sweta
authors.initials: S
authors.lastname: Pandey
authors.forename: Ravi
authors.initials: R
authors.lastname: Ranjan
authors.forename: Vineet
authors.initials: V
authors.lastname: Shah
authors.forename: Rahasya Mani
authors.initials: RM
authors.lastname: Mishra
authors.forename: Monica
authors.initials: M
authors.lastname: Sharma
authors.forename: Renu
authors.initials: R
authors.lastname: Saxena
mesh_terms: D000755:Anemia, Sickle Cell / Q000150:complications / Q000235:genetics* / Q000473:pathology*; D002648:Child; D005260:Female; D018628:Gene Dosage; D006801:Humans; D007194:India; D008297:Male; D010641:Phenotype; D055542:alpha-Globins / Q000235:genetics*; D017086:beta-Thalassemia / Q000150:complications / Q000235:genetics* / Q000473:pathology*
chemical_list: D055542:alpha-Globins
keywords: ARMS-PCR; Gap-PCR; SCD; sickle β-thalassemia; α-thalassemia