Point mutations on mitochondrial DNA in Iranian patients with Friedreich's ataxia

Mitochondrial DNA [mt DNA] is considered a candidate modifier factor for neuro-degenerative disorders. The most common type of ataxia is Friedreich's ataxia [FA]. The aim of this study was to investigate different parts of mt DNA in 20 Iranian FA patients and 80 age-matched controls by polymerase chain reaction [PCR] and automated DNA sequencing methods to find any probable point mutations involved in the pathogenesis of FA. We identified 13 nucleotide substitutions including A3505G, T3335C, G3421A, G8251A, A8563G, A8563G, G8584A, T8614C, T8598C, C8684T, A8701G, G8994A and A9024G. Twelve of 13 nucleotide substitutions had already been reported as polymorphism. One of the nucleotide substitutions [A9024G] had not been reported before. The A9024G nucleotide substitution does not change its amino acid. The controls were also investigated for this polymorphism which was found in two of them [2.5%].None of the mutations found in this study can affect the clinical manifestations of FA. This survey also provides evidence that the mtDNA A9024G allele is a new nonpathogenic polymorphism. We suggest follow-up studies for this polymorphism in different populations

Sequencing and expression of elastase 11 gene in polymorphoneuclear leukocytes in healthy individuals for determination of single nucleotide polymorphism [SNP] by RT-PCR

ELA2 gene responsible for coding human neutrophil elastase, a powerful serine protease carried by blood neutrophils and capable of destroying most connective tissue proteins. The NE gene consist of 5 exons and 4 introns. Peripheral blood obtained from healthy individuals. Total RNA was isolated using RNA standard techniques from fresh separated cells by polymorphoprep. RNA was analyzed by employing PCR amplification of reveres transcribed using a total of ten specific primers. We amplified five exon of ELA2 gene separately and sequenced each exon. Mutational analysis was performed by directed capillary sequencing method. We have found new single nucleotide polymorphism [SNP] in exon II codon 44. It was a silent mutation G to A substitution but no changes in amino acid sequences were seen. The codon sequence was GCG that has changed to GCA. The purpose of SNP detection is mainly recognition of susceptible people to certain diseases and providing suitable drugs based on each person genetic information. SNP information in Iranian patients can be used for analysis of drug response to human diseases

[Prenatal diagnosis of human fetal Rh blood group by heminested-PCR]

Background: The rhesus blood group antigen system is important in transfusion and clinical medicine, being involved in hemolytic disease of the newborn, transfusion reactions and autoimmune hemolytic anemia. Despite the widespread use of rhesus immunoglobulin prophylaxis in rhesus D [RhD]-negative mothers, rhesus immunization still occurs. Knowledge of the RhD status of the fetus is important in the clinical management, because no further diagnosis or therapeutic procedures are necessary if the fetus is RhD-negative. RhD antigen can be detected using a sensitive PCR-based assay. It was shown that RhD negative individuals lack the RhD gene

Methods: We obtained 5m1 blood samples from thirty eight RhD positive and negative blood donors, as controls and forty chorionic villus samples [CVS] from pregnant women at 8 to 12 weeks of gestation DNA was extracted from CVS by standard salting out and blood DNA was extracted by boiling procedure. DNA amplification [heminested-PCR] was carried out with appropriate primers

Results: PCR products were analyzed on an agarose gel. RhD gene determined in all CV samples