Combination of hb Knossos [Cod 27 (G-T)] and IVSII-745 (C-G) in a Turkish patient with beta-thalassemia major

Keser I., Manguoglu E., Kayisli O., Yesilipek A., Luleci G.

GENETIC TESTING, vol.11, no.3, pp.228-230, 2007 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 11 Issue: 3
  • Publication Date: 2007
  • Doi Number: 10.1089/gte.2006.0521
  • Journal Name: GENETIC TESTING
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.228-230
  • Akdeniz University Affiliated: No


Beta-thalassemia is the most common disease among hemoglobinopathies in Antalya, Turkey, as well as worldwide. Mutations found in Turkish beta- thalassemia patients constitute a heterogeneous group, consisting mostly of point mutations. Only in very rare cases did deletions or insertions cause affected or carrier phenotypes. Hb Knossos [beta 27 (B9) Ala-Ser] is a rare variant with a normal HbA2 level. In this study, we aimed to investigate the effect of compound heterozygosity for Hb Knossos [Cod 27 (G-T)] and IVSII-745 (CG). To our knowledge, this is the first report of such a combination related with beta- thalassemia major phenotype in a Turkish family, where reverse dot blot hybridization (RDBH) and DNA sequencing analysis were used. Heterozygous inheritance of the mutation results in mild beta-thalassemia phenotype, whereas homozygous inheritance leads to intermediate beta-thalassemia. As a result, the compound heterozygosity of Hb Knossos with IVSII-745 appears as the cause of the beta-thalassemia major phenotype in our case. The combination of these mutations [Hb Knossos, Cod 27 (G-T), and IVSII-745, C-G] causes the beta-thalassemia major phenotype, and this is important for genetic counseling.