Molecular analysis of A2-genes encoding stage-specific s antigen-like proteins among isolates from iranian cutaneous and visceral leishmaniasis

Leishmania can lead to a broad spectrum of diseases, collectively known as leishmaniasis. The A2 gene/ protein family could be one of the most eligible candidate factors of virulence in visceral leishmaniasis [VL]. The previous results confirmed that in Leishmania infantum, several A2 proteins are abundantly expressed by the amastigote, but not the promastigote stage. As there are no data available on the pattern of A2 gene / protein in Iranian Leishmania isolates of either cutaneous leishmaniasis [CL] or VL; the current study aimed to investigate molecular analysis of A2 gene in leishmania species among field isolates of Iran. An A2 gene was identified by sequencing of crude PCR products resulting from 20 samples of CL and 10 samples of VL isolates from Iranian patients. The results indicated the A2 gene in CL is only a single copy of 153 bp encoding a protein of 51 amino acids, as opposed to A2 of VL species with multi-copy genes of varying length. A2 sequences in Iranian L. major strains represented a homology with stage-specific S antigen-like protein [A2] of L major and L infantum. Moreover, A2 sequences in Iranian L. tropica strains have homology with A2 protein of L. major and L. tropica. It is concluded that A2 is an antigen candidate for vaccine development and diagnosis purposes and that A2 sequences are conserved among field isolates

ATM gene mutations detection in Iranian Ataxia-Telangiectasia patients

Ataxia-Telangiectasia [AT] is an autosomal recessive disorder involving cerebellar degeneration, immunodeficiency, radiation sensitivity and cancer predisposition. The ATM gene on human chromosome 11q22.3 has recently been identified as the gene responsible for ataxia-telangiectasia [AT]. The gene mutated in AT, which has been designated as the ATM gene, encodes a large protein kinase with a PI-3 kinase-related domain. More than 100 mutations are broadly distributed throughout the ATM gene. The large size of the ATM gene [66 exons spanning approximate 150kb of genomic DNA] together with the diversity and broad distribution of mutations in AT patients, greatly limits the utility of direct mutation screening as a diagnostic tool. In this study, 20 families with at least one affected child clinically suspected to have ataxia-telagiectasia were examined and their DNA was extracted and amplified with standard methods. Sequencing methods were used to detect the new point mutation. Four exons which were hot spots for point mutations in ATM gene were detected by PCR-SSCP or PCR-RFLP