Rate of Heterozygosity of two Short Tandem Repeat Markers from Chromosome ۱۸ in Iranian Population

Background: Preimplantation genetic screening (PGS) involvesbiopsy of a single cell from a cleavage stage embryofertilized through intra-cytoplasmic sperm injection (ICSI).Majority of women seeking assisted reproductive techniques(ART) are women older than ۳۵ years olds and PGS may helpsuch couples to select embryos with normal chromosomal complement.PGS screens the embryos for numerical chromosomalabnormalities including trisomies ۱۳, ۱۸ and ۲۱. Trisomy ۱۸(Edwards syndrome) is caused by an error in meiotic disjunction.Quantitative Fluorescence-Polymerase Chain Reaction(QF-PCR) is a technique for detection of aneuploidies in prenatalstage and works based on heterozygosity of short tandem repeat(STR) markers for particular chromosomes. With the aimof setting up this method in preimplantation stage we evaluatedthe heterozygosity and polymorphic rate of D۱۸S۹۷۶ andD۱۸S۵۳۵ STR markers in Iranian population.Materials and Methods: Genomic DNA was extracted fromperipheral blood of a total of ۵۰ healthy men and women.D۱۸S۹۷۶ and D۱۸S۵۳۵ STR markers were amplified usingspecific primers and multiplex PCR. The PCR products wererun on acrylamide gel and the percent of heterozygosity of eachmarker was calculated separately.Results: We observed homozygote genotype for D۱۸S۳۹۷۶and D۱۸S۵۳۵ markers in ۳۲ and ۳۸% of the cases, respectively.Therefore, ۶۸ and ۶۲% of cases were heterozygote for D۱۸S۹۷۶and D۱۸S۵۳۵ markers, in respect.Conclusion: Previous studies have reported D۱۸S۹۷۶ andD۱۸S۵۳۵ as informative markers in diagnosis of trisomy ۱۸in other populations. According to our results, these markersseems to be relatively informative of trisomy ۱۸ for Iranianpopulation as well, although it is necessary to be evaluated inlarger population.

کلیدواژه ها:

Preimplantation Genetic Screening ، Short Tandem Repeats ، Trisomy ۱۸ ، D۱۸S۹۷۶ ، D۱۸S۵۳۵