الفهرس 
DNA structure and Repetitive DNAOnly 14 pages are availabe for public view
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Abstract
Background: The variable number tandem repeats (VNTR) are highly polymorphic markers. Due to their high polymorphic content, VNTR constitute useful tools in population genetic studies in understanding population and ethnic migrations throughout history. They also constitute preferred systems for DNA “fingerprinting”, criminal and forensic examinations and paternity testing, evaluating hematopoietic chimerism and in determining the origin of leukemic cells in patients with recurrent disease after BMT.
Aim of the Work: To standardize PCR protocols of 2 VNTR loci (D1S111/33.6 and 33.4) in order to detect allelic polymorphism among Egyptians as a tool in following up the chimeric status after allogenic stem cell transplantation.
Patients and Methods: The current study was conducted at Clinical Pathology Department of Ain Shams University Hospital between January 2018 and December 2019, a total of 130 subjects [65 pairs (allogenic stem cell transplantation donors and their recipients)] were included. D1S111/33.6 and 33.4 VNTR loci were evaluated in every subject by PCR technique to study their relative distribution and number of informative alleles detected in order to be used in chimerism follow up and population studies.
Results: Five alleles were found at D1S111/33.6 in 130 subjects with molecular weight ranging from 364 to 993 bp, frequency of homozygous alleles were 30.8% and it was 69.2% for heterozygous, 90 out of the total 130 subjects were heterozygous for 33.6, that means that the heterozygosity index for D1S111/33.6 is 69.2%, from the 65 pairs tested 31 pair were informative or discriminative with discriminative power 47.69%. For 33.4 we tried many PCR programs but no bands were detected at all.
Conclusion: D1S111/33.6 VNTR polymorphism is a dependable cost effective method in following up of allogenic stem cell transplantation recipients.