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Facioscapulohumeral muscular dystrophy (FSHD) is associated with the contraction of the D4Z4 macrosatellite in the 4q35 subtelomeric region. The most common technique for genetic diagnosis of FSHD is Southern Blotting which is tedious, difficult to interpret, and involves radioactive labelling, which limits its availability. We explored the potential of a new technique, called Optical Genome Mapping (OGM) with the Saphyr system from Bionano Genomics for FSHD detection. Based on our validation study, we conclude that OGM is a powerful and robust technique for FSHD testing in genetic diagnostic laboratories, providing results that are completely concordant with the current gold standard Southern Blot analysis.