Rapid screening of β-Globin gene mutations by Real-Time PCR in Egyptian thalassemic children

Thalassemia is one of the most common genetic disorders in Egypt. With the total population of 70 million, there are approximately 600,000 affected individuals and more than 20 million thalassemia carriers. Thalassemia is therefore one of the major health problems in Egypt. B-Thalassemias are priority genetic diseases for prevention programs. Rapid genotype characterization is fundamental in the diagnostic laboratory, especially when offering prenatal diagnosis for carrier couples. Introduction of the real time PCR has made a revolution in the time taken for the PCR reactions. We present a method for the diagnosis of the common mutations of the B-thalassemia in Egyptian children & families. The procedure depends on the real-time PCR using specific fluorescently labeled hybridization probes. The melting temperature for each of the specific probes obtained after the PCR reaction permits the identification of the specific mutation. Genotyping of 20 thalassemic children attending the hematology clinic of the children specialized hospital and 10 controls was done using Real-time PCR and the conventional Amplification Refractory Mutation System (ARMS) technique. Analysis revealed identical results to most of the patients and they were further checked by the sequencing results of the DNA samples. The established method is a robust, fast and straight forward assay that allows the detection of the common B-thalassemia mutations in Egypt. The described LightCycler system protocol can rapidly screen for many B-globin gene mutations. African Journal of Health Sciences Vol. 13 (3-4) 2006: pp. 70-7

Molecular characterization of chromosome 7 in AML and MDS patients

Myelodysplastic syndromes (MDS) share many features with acute myeloid leukemias (AML) and in fact 20 - 40% of the patients eventually develop a picture of full blown AML. Chromosome 7 has been a focus of attention as a site harboring tumor suppressor genes whose loss of function contributes to leukemia transformation or tumor progression. Abnormalities of chromosome 7 are frequently encountered in AML and MDS. The aim of the present study was to detect the molecular abnormalities of chromosome 7 in Egyptian AML and MDS patients using the FISH technique and whether the abnormality has an implication on the prognosis of the disease after a period of one year follow up. Fluorescence in-situ hybridization (FISH) was performed for chromosome 7 using a locus specific probe for 7q31 and a centromeric probe from 7p11.1-q11.1 in a series of 30 patients diagnosed as: AML (20 patients) and MDS (10 patients) according to the FAB criteria. Aberrations of Chromosome 7 were found in 36.6% of AML patients: 3 cases showing monosomy with a mean positivity of 17.3%, 2 cases showing 7q deletion with a mean positivity of 11%. While both monosomy and deletion were detected in 3 cases. However, in MDS patients; monosomy for chromosome 7 was the only abnormality detected and was found in 30% of cases. Genetic abnormality of chromosome 7 showed a significant association with poor prognostic criteria. Patients who had normal FISH results showed a higher percentage (31.6%) of complete remission (CR) versus 0% in patients with monosomy or deletion who showed a higher percentage (100%) of death or poor response to therapy (NR). Although AML patients had a worse prognosis when compared to MDS patients, patients with genetic abnormalities showed the worst outcome. African Journal of Health Sciences Vol. 13 (3-4) 2006: pp. 33-4