A novel 33.3 kb deletion (- -KOL) in the alpha-globin gene cluster: a brief report on deletional alpha-thalassaemia in the heterogeneous eastern Indian population.

We have detected, in three unrelated eastern Indian individuals, a hitherto unreported alpha zero deletion, - -KOL, in the heterozygous state, encompassing the embryonic zeta2-globin and the duplicated alpha-globin genes extending from c. 1150 bp upstream of the zeta2 globin gene to c. 960 bp downstream of the theta1 gene. Other deletions present in 120 unrelated, eastern Indian, putative alpha-thalassaemia patients are -3.7 kb (16.25%), -4.2 kb (5%) and - -SEA (3.33%).

Profile of beta-thalassemia in eastern India and its prenatal diagnosis.

OBJECTIVE: To control the birth of thalassemic children in India. METHODS: Mutations present in the population of eastern India and in carrier parents seeking prenatal diagnosis were detected by the PCR-based technique of ARMS (amplification refractory mutation system) or gap-PCR. To screen for maternal tissue contamination in CVS, haplotypes associated with the beta-globin gene clusters were constructed using six polymorphic restriction sites. Prenatal diagnosis was accomplished by checking presence of parental mutation in the DNA from chorionic villus sampling (CVS) collected at 8 to 10 weeks' gestation by appropriate technique. RESULTS: Six hundred and fifty (650) unrelated beta-thalassemia chromosomes were screened for 11 common mutations to characterize the mutation distribution in this population. Starting from early 2000, 63 families from different parts of West Bengal and from surrounding areas have been offered prenatal counseling for beta-thalassemia. CONCLUSION: The population of this region is conscious and willing to accept prenatal diagnosis as a means of control of thalassemia.