Equalized statistics on the graph can help identify chromosome abnormalities in twins (such as those which cause Edwards syndrome and Down syndrome) and also help determine the gender of fetuses. According to a 2012 report published in Parental Diagnosis, traditional chromosome testing identified 7 Down syndrome cases in 4644 samples. Two of these cases involved identical twins with abnormalities in chromosome 21, and other cases involved a single fetus. In a separate case, patau syndrome was found in one of the twins. Samples from the 7 Down syndrome cases were re-tested with NIPS, and NIPS results were found to be accurate. Furthermore, samples from 17 normal twin cases and 2 normal triplet cases were also tested using NIPS, and these results were accurate as well.