Screening of dystrophin gene deletions in Egyptian patients with DMD/BMD muscular dystrophies

Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are allelic disorders caused by mutations within the dystrophin gene. Our study has identified 100 Egyptian families collected from the Human Genetics Clinic, National Research Center, Cairo. All cases were subjected to complete clinical evaluation pedigree analysis, electromyography studies, estimation of serum creatine phosphokinase enzyme (CPK) levels and DNA analysis. Multiplex PCR using 18 pairs of specific primers were used for screening of deletion mutations within the dystrophin gene. A frequency of 55% of deletions were found among the families. Sixty per cent of detected deletions involved multiple exons spanning the major or the minor hot spot of the dystrophin gene. The remainder 40% involved single exon deletions, which mainly involved exon 45. Comparing these findings with frequencies of other countries it was found that our figures fall within the reported range of 40%-60% for deletions. The distribution of deletions in our study and other different studies was variable and specific ethnic differences do not apparently account for specific deletions. In addition this study concluded that employment of the 18 exon analysis is a cost effective and a highly accurate (97% detection rate) method to be considered when planning to launch a nationwide program

Clinical and molecular findings in eight Egyptian patients with suspected mitochondrial disorders and optic atrophy

AbstractMitochondrial respiratory chain disorders (RCD) are a group of genetically and clinically heterogeneous diseases, caused due to defects of the respiratory chain. This study aimed to investigate the presence of common mtDNA point mutations in tRNALeu (UUR), tRNALys, MT-ATPase 6, MT-ND4, MT-ND1, MT-ND6 genes in eight Egyptian patients suspected to have mtDNA disease and optic atrophy.PCR-RFLP analysis was done for the detection of 3243A>G, 3271T>C, 8344A>G, and 8993T>G/C mtDNA point mutations. DNA direct sequencing was pursued for the detection of 11778G>A, 3460G>A and 14484T>C mtDNA point mutations. No point mutation of 3243A>G, 3271T>C, 8344A>G, and 8993T>G/C was detected in our group of patients. Four mtDNA polymorphisms in MT-ND1 and MT-ND4 genes (11467A>G, 11719G>A, 3348A>G and 3357G>A) were detected in three patients.Mitochondrial disorders are caused by a variety of genetic and racial factors, which differ among populations. The negative results of this study indicate that the chosen mutations might not be specific in Egyptians. Another explanation might be due to the low heteroplasmic levels of the mtDNA mutation. A registry for the different mtDNA mutations in Egyptian patients is highly recommended

Screening of Dystrophin Gene Deletions in Egyptian Patients with DMD/BMD Muscular Dystrophies

Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are allelic disorders caused by mutations within the dystrophin gene. Our study has identified 100 Egyptian families collected from the Human Genetics Clinic, National Research Center, Cairo. All cases were subjected to complete clinical evaluation pedigree analysis, electromyography studies, estimation of serum creatine phosphokinase enzyme (CPK) levels and DNA analysis. Multiplex PCR using 18 pairs of specific primers were used for screening of deletion mutations within the dystrophin gene. A frequency of 55% among the families. Sixty per cent of detected deletions involved multiple exons spanning the major or the minor hot spot of the dystrophin gene. The remainder 40% which mainly involved exon 45. Comparing these findings with frequencies of other countries it was found that our figures fall within the reported range of 40%– for deletions. The distribution of deletions in our study and other different studies was variable and specific ethnic differences do not apparently account for specific deletions. In addition this study concluded that employment of the 18 exon analysis is a cost effective and a highly accurate (97% to launch a nationwide program