Common genotypes of hepatitis B virus

To find out the frequency of common genotypes of hepatitis-B virus [HBV] Design: An analytical study. Place and Duration of Study: The present study was carried out at Division of Infectious Diseases and Molecular Diagnostics, Centre for Applied Molecular Biology, Ministry of Science and Technology, Lahore, Pakistan from May 2002 to February 2004. Subjects and HBV genotypes were determined in 112 HBV DNA positive sera by a simple and precise molecular genotyping system based on PCR using type-specific primers for the determination of genotypes of HBV A through H. Four genotypes [A, B, C and D] out of total eight reported genotypes so far were identified. Genotypes A, B and C were predominant. HBV genotype C was the most predominant in this collection, appearing in 46 samples [41.07%]. However, the genotypes of a total of 5 [4.46%] samples could not be determined with the present genotyping system. Mixed genotypes were seen in 8 [7.14%] HBV isolates. Five of these were infected with genotypes A/D whereas two were with genotypes C/D. One patient was infected with 4 genotypes [A/B/C/D]. Genotype A [68%] was predominant in Sindh; genotype C was most predominant in North West Frontier Province [N.W.F.P.] [68.96] whereas genotypes C and B were dominant in Punjab [39.65% and 25.86% respectively]. All the four common genotypes of HBV found worldwide [A, B, C and D] were isolated. Genotype C is the predominant. Genotypes B and C are predominant in Punjab and N.W.F.P whereas genotype A is predominant in Sindh

Molecular genetic diagnosis of beta thalassemia in Pakistan

A set of procedures, based on DNA analysis, has been developed to detect deletions and point mutations causing Beta thalassemia in the Pakistani population. These procedures can be used to analyze the presence of relevant changes in DNA, thus providing a reliable means for screening the high risk families, to provide them genetic counseling and prenatal diagnosis during early pregnancy. We have identified two mutations IVS-1 nt.5 [G--C] and codon 8-9 [+G] in 4 of the 6 families analysed for these mutations

Isolation of DNA methylase modification enzyme

Type II restriction endonuclease was isolated from locally isolated strain Enterobacter cloaca of recognition sequence CGATCG. Its cognate methylase was isolated and its 5 methyl Cytosine was confirmed by methylation and DNA hydrolysis