Algorithm-Based Fetal Gender Determination Using X and Y Mini-Short Tandem Repeats at Early Gestational Ages

Background: detection of fetal dna in maternal blood has been examined by many research groups for a few years; thereby, scientists have a shorter way to take to approach prenatal diagnosis of abnormal pregnancies. the y chromosome sequences have recently become the most common applicable indices for fetal sex determination. objectives: we conducted an algorithmic x and y mini-short tandem repeats (strs) genotyping method that could solve the problem of false negative (no detection of y sequences) results of previous methods. patients and methods: blood samples were obtained from 106 pregnant women and their spouses. conventional pcr amplified 19 mini-short tandem repeats (strs) and three non-str markers, which were subsequently genotyped by the means of polyacrylamide gel electrophoresis (page).results: sensitivity and specificity of the mini-str genotyping method for fetal dna detection were calculated (95.9% and 98%, respectively) with a confidence interval of 95%. in addition, sensitivity and informativeness were computed for each of the single mini-str markers in our conventional pcr method. we also introduced the minimum number of mini-strs needed to reach maximum validity for fetal gender determination in clinical settings. conclusions: algorithm-based mini-str genotyping method significantly increases the reliability (sensitivity and specificity) of gender determination using free fetal dna and could be applied in prenatal clinical testing.