Alpha thalassaemia in Yemeni children with sickle cell disease

Abstract

Alpha thalassaemia frequently occurs in several of the Middle Eastern populations. This study was conducted on 26 sickle cell disease (SCD) patients from Yemen and 19 normal children (Hb AA) living in Riyadh, Saudi Arabia. Blood samples were extracted by venepuncture, and haematological acid biochemical parameters were estimated. DNA was extracted from the buffy coat and analysed for α-gene arrangement using Bam HI and Bgl II. The frequency of α-gene deletion in the total Yemeni group (26 SCD + 19 Hb AA) was 0.311 for one α-gene deletion (-α/αα) and 0.13 for two α-gene deletions (-α/-α). When separated on the basis of the Hb phenotype the α-gene deletion frequency was significantly higher (-α/αα = 0.346 and -α/-α = 0.231) in the SCD patients compared to the normal Hb AA group (-α/αα = 0.263 and -α/-α = 0). In the Hb AA group one child had triple α-gene arrangement (ααα/αα) giving an overall frequency of triple α-gene as 0.022. Haematological parameters showed variations in the SCD patients with and without α-gene deletion. This paper shows for the first time that α-gene deletion occurs in the Yemenis and the frequency is higher in patients with SCD. Further population-based studies are required to determine the exact frequency of the different types of α-thalassaemias in the overall Yemeni population.