Oligonucleotide array for detection of common severe determinants of alpha thalassemia

A simple and an efficient oligonucleotide array was developed to identify common severe determinants of alpha (α) thalassemia. A total of 14 probes were designed to detect the most frequently three deletions (-α3.7, -α4.2, -SEA) and two non-deletions (αQuongSze, αConstantSpring). PCR products were amplified from human genomic DNA and allowed to hybridize with the oligonucleotide array. Hybridization was detected by fluorescence scanning, and α globin genotypes were assigned by quantitative analysis of the hybridization results. The efficiency and specificity of identifying α globin genotypes using the oligonucleotide arrays was evaluated by blinded analysis of 690 samples from unrelated individuals. The oligonucleotide array method described in this paper provides unambiguous detection of complex combinations of heterozygous, compound heterozygous and homozygous α thalassemia genotypes. The experimental results demonstrate that this methodological approach may be applied for screening and for hemological diagnosis in population at large.