title: Evaluation of Alpha-Thalassemia Mutations in Cases with Hypochromic Microcytic Anemia: The İstanbul Perspective.
abstract: OBJECTIVE
  Alpha thalassemia syndromes are caused by mutations on one or more of the four α-globin genes. Mutations could be either more commonly deletional or non-deletional. As some deletions (3.7 and 4.2) cause α+-thalassemia, some cause (-20.5, MED, THAI, FIL) α0 -thalassemia. The aim of this study was to determine alpha thalassemia mutations in patients with unsolved hypochromic microcytic anemia and to evaluate types of mutations.
  
  
  METHODS
  Two hundred six patients with hypochromic microcytic anemia were evaluated for alpha thalassemia. A venous blood sample of 2 mL was drawn from each patient for DNA isolation. The samples were investigated for α-thalassemia mutations by using the Vienna Lab α-Globlin StripAssay TM commercial kit.
  
  
  RESULTS
  Fourteen different mutations were determined in 95 (46.1%) patients. The most common mutation was the 3.7 single gene deletion and was found in 37 patients (n=37/95, 39%). Others common mutations were the 20.5 kb double gene deletion (n=20 patients, 21%), MED double gene deletion (n=17 patients, 17.9%), α2 IVS1 (n=10 patients, 10.5%), α2 cd142 Hb Koya Dora (n=6 patients, 6.3%), α2 polyA1 (Saudi type) (n=6 patients, 6.3%), 4.2 single gene deletion (n=4 patients, 4.2%), α1 cd14 (n=2 patients, 2.1%), and -FIL mutation (n=2 patients 2.1%), respectively. Hb Adana, Hb Icaria, α2 init cd and α2 polyA2 (Turkish type) were found in 1% of the patients (n=1). Seven patients (7.4%) had α-thalassemia triplication. In our study, three mutations (Hb Icaria, α1 cd14, α2 init.cd) were determined firstly in Turkey. Seven mutations (-SEA, -THAI, Hb Constant Spring, α2 cd19, α2 cd59, α2 cd125, Hb Paksé) were not determined in this study.
  
  
  CONCLUSIONS
  Alpha thalassemia should be considered in the differential diagnosis of hypochromic microcytic anemia especially in cases without iron deficiency and b-thalassemia carrier state. Genetic testing should be performed for the suspicious cases. We also recommend that a national database with all mutations in Turkey should be created to screen the alpha thalassemia cost-effectively.
authors.forename: Zeynep
authors.initials: Z
authors.lastname: Karakaş
authors.affiliation: İstanbul University İstanbul Faculty of Medicine, Department of Pediatric Hematology-Oncology, İstanbul, Turkey Phone: +90 505 906 27 91 E-mail: begumsirins@hotmail.com.
authors.forename: Begüm
authors.initials: B
authors.lastname: Koç
authors.forename: Sonay
authors.initials: S
authors.lastname: Temurhan
authors.forename: Tuğba
authors.initials: T
authors.lastname: Elgün
authors.forename: Serap
authors.initials: S
authors.lastname: Karaman
authors.forename: Gamze
authors.initials: G
authors.lastname: Asker
authors.forename: Genco
authors.initials: G
authors.lastname: Gençay
authors.forename: Çetin
authors.initials: Ç
authors.lastname: Timur
authors.forename: Zeynep Yıldız
authors.initials: ZY
authors.lastname: Yıldırmak
authors.forename: Tiraje
authors.initials: T
authors.lastname: Celkan
authors.forename: Ömer
authors.initials: Ö
authors.lastname: Devecioğlu
authors.forename: Filiz
authors.initials: F
authors.lastname: Aydın
mesh_terms: D000293:Adolescent; D000328:Adult; D000483:Alleles; D000747:Anemia, Hypochromic / Q000453:epidemiology / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D004252:DNA Mutational Analysis; D005260:Female; D017353:Gene Deletion; D020440:Gene Duplication; D005838:Genotype; D006455:Hemoglobins, Abnormal / Q000235:genetics; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D009154:Mutation; D017384:Sequence Deletion; D014421:Turkey / Q000453:epidemiology; D055815:Young Adult; D055542:alpha-Globins / Q000737:chemistry / Q000235:genetics*; D017085:alpha-Thalassemia / Q000097:blood / Q000453:epidemiology / Q000235:genetics*
chemical_list: D006455:Hemoglobins, Abnormal; D055542:alpha-Globins