Optical Genome Mapping

Standard cytogenetics (CBA +/- FISH) is of diagnostic and prognostic interest in Ph- MPN. However, its value is limited by the low frequency of detected abnormalities. The development of tools to increase the sensitivity of detection of chromosomal alterations is therefore particularly adapted to these pathologies. Optical genome mapping (OGM) is a high resolution "long read" technique that allows the identification of structural and copy number variations at the whole genome level. Several recent studies suggest that OGM is a future tool for cytogenetic characterization of haematological disorders. Its ability to describe structural abnormalities, including balanced ones, represents a major advantage over currently used technologies. Thus, OGM seems to be the key tool for cytogenetics of haematological malignancies in the coming years, making it possible to replace, under certain conditions, not only karyotype and FISH, but CMA and even RT-MLPA for the search for fusion transcripts, thus filling in the gaps in these techniques while maintaining their advantages. To define the place of this technology in Ph- MPN, the investigators will perform a OGM analysis on patients with Ph-MPN for whom bone marrow exploration is scheduled. These results will be compared with those of standard cytogenetics (CBA +/- FISH).

Orofacial clefts, the most common congenital craniofacial malformations, have a complex etiology involving an interaction between genetic and environmental factors. Chromosomal abnormalities, including structural variations, represent a major cause of human pathology. Recently, technological developments and the introduction of next-generation sequencing (NGS) technologies have revolutionized the field of medical genetics. Optical genome mapping (OGM) is an innovative, high-resolution "long read" technique that enables the identification of all classes of chromosomal variation, consisting in the direct visualization of long, labeled DNA molecules throughout the genome. This technology is gradually becoming an essential tool for studying onco-hematology and constitutional genetic pathologies The purpose of this study is to search for structural chromosomal variants (SV) or copy number variants (CNV) not identifiable either by cytogenetic methods nor by "short read" NGS "short read, in individuals with oral-facial clefts with no genetic diagnosis.