I'm working on NIPT projects and my results saw numerous of false positive and false negative reports. During one of my study I found many papers mentioned about the effect of maternal CNV on the NIPT result. However, I cannot found any data about the coordinate of common CNV area (especially those on chromosome 13,18 and 21). Also from what I study my method to identify regions that only contain unique reads by splice the normal fasta sequence to multiple small sequences does not cover all repetitive, some area like the p band of chromosome 21 still be chosen for some regions. Can someone tell me where can I access to the coordinate of common CNV and repetitive areas? Thank you very much