Editor—The autosomal recessive disease β thalassaemia is a common single gene disorder that poses a serious health problem in many parts of the world. According to the Human Gene Mutation Database (http://www.uwcm.ac.uk/uwcm/mg/hgmd.html) and the β-Globin Gene Server (http://globin.cse.psu.edu) about 300 sequence variants in the β globin gene have been identified up to the present. Mutations in the β globin gene have been found at carrier frequency rates ranging from 1% in some areas of Saudi Arabia to 15% in others.1 Both β° and β⁺ thalassemia have been reported.2 Studies on the molecular pathogenesis of β thalassaemia have shown that the mutations encountered in Arab countries close to the Mediterranean basin are the same as those reported in other Mediterranean populations.3 In the Gulf region, in Saudi Arabia, UAE, and Iraq, the Asian pattern of mutations seems to be prevalent.4 5 The precise genetic changes prevalent in the different regions of the large country of Saudi Arabia and analysis of the genotype/phenotype relationship of the disease in Saudi patients still remain inadequately studied.

The present study aimed to investigate the mutational pattern of the β globin gene and to explore the relationship between these mutations and disease presentation in a group of patients with β thalassaemia major from the eastern region of Saudi Arabia. For this purpose, 31 children diagnosed with β thalassaemia major who over the past two years had regularly attended the paediatric clinics of Qatif Central Hospital or Dammam Maternity and Children Hospital were selected. Within this group of patients there were four pairs of sibs and one pair of first cousins. The whole β globin gene of all patients was amplified using standard PCR techniques and six specially designed different primers for …