title: Accuracy of Reverse Dot-Blot PCR in Detection of Different β-Globin Gene Mutations.
abstract: Prevention programs for β-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 β-globin gene mutations in Egyptian children with β-thalassemia. Forty children with β-thalassemia were subjected to mutation analysis, performed by both direct DNA sequencing and β-globin Strip Assay MED™ (based on reverse dot-blot PCR). The most frequent mutant alleles detected by reverse dot-blot PCR were; IVSI-110 G>A (31.25 %), IVS I-6 T > C (21.25 %), and IVS I-1 G>A (20 %). Relatively less frequent mutant alleles detected by reverse dot-blot PCR were "IVSII-1 G>A (5 %), IVSII-745 C>G (5 %), IVSII-848 C>A (2.5 %), IVSI-5 G>C (2.5 %), -87 C>G(2.5 %), 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 β-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.
authors.affiliation: Clinical Pathology, Tanta University, Tanta, Egypt.
authors.forename: N
authors.initials: N
authors.lastname: El-Fadaly
authors.affiliation: Clinical Pathology, Tanta University, Tanta, Egypt.
authors.forename: A
authors.initials: A
authors.lastname: Abd-Elhameed
authors.affiliation: Clinical Pathology, Tanta University, Tanta, Egypt.
authors.forename: E
authors.initials: E
authors.lastname: Abd-Elbar
authors.affiliation: Pediatric Departments, Tanta University, Tanta, Egypt ; Faculty of Medicine, Tanta University, Tanta, Gharbia Egypt.
authors.forename: M
authors.initials: M
authors.lastname: El-Shanshory
keywords: DNA sequencing; Genetic mutations; β-Globin Strip Assay MED™ (reverse dot-blot PCR); β-Thalassemia