Prevention programs for b-thalassemia based on molecular diagnosis of heterozygous carriers and/or patients require the use of reliable mutation screening methods. The aim of this study was to compare between direct DNA sequencing, and reverse dot-blot PCR in detection of different b-globin gene mutations in Egyptian children with b-thalassemia. Forty children with b-thalassemia were subjected to mutation analysis, performed by both direct DNA sequencing and b-globin , and cd39 C[T (2.5 %)'', While the genotypes of three patients (6 alleles 7.5 %) were not detected by reverse dot-blot PCR. Mutant alleles detected by direct DNA sequencing were the same as reverse dot-blot PCR method except it revealed the genotypes of 3 undetected patients (one patient was homozygous IVSI-110 G[A, and two patients were homozygous IVS I-1 G[A. Sensitivity of the reverse dot-blot PCR was 92.5 % when compared to direct DNA sequencing for detecting b-thalassemia mutations. Our results therefore suggest that, direct DNA sequencing may be preferred over reverse dot-blot PCR in critical diagnostic situations like genetic counseling for prenatal diagnosis.

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