Particular Microdeletion and Microduplication Syndromes (MMS) are rare recombinations, but as a whole (cumulatively) they represent a significant group of genetic abnormalities almost equal to aneuploidies. Some of them and in particular Di George Microdeletion can be found in frequencies second only to trisomy 21. Based on our database of MMS we found that almost all MMS span in length less than 5Mbs which is the cut-off point of resolution in standard cytogenetics. Furthermore, a significant percentage of them are in length less than 0.5Mbs and all together, short and long MMS, have a high probability to harbor Holliday Junction sequence motifs and PRDM9 sequence motifs.

Collectively, we propose that HJ sequence motifs and other recombination primers such as PRDM9 binding motif that exist in regions spanning MMS hotspots underlie a possible mechanism for their occurrence during probably in gametogenesis.

In this context, we created the GeneScreening, a web-based system, a tool that allows for the advanced processing of user genomic data, along with visualization tools to identify and display the regions of interest regarding MMS in reference with the sequence motifs of HJs and PRDM9. This system will provide useful information for potential drug targets and new strategies for individual therapy as it serves as a prognostic tool for the MMS referenced in this paper.