Validation Study of Optical Genome Mapping for Postnatal and Prenatal Clinical Testing According to Established NYSDOH Guidelines

Giemsa banding (GTG-Banding) is a conventional cytogenetic analysis that allows for the identification of balanced and unbalanced structural and numerical chromosome abnormalities with a diagnostic yield of about 3%. Fluorescence in situ hybridization (FISH) is targeted to a particular chromosomal region or regions specifically indicated by the patient’s phenotype. Chromosome microarray array (CMA) aids in the identification of copy number variants (CNVs) with a diagnostic yield of about 10%-15%. Currently, CMA is a tier-1 test for aneuploidy and unbalanced structural chromosome abnormalities (SVs; CNVs), some types of ploidy and regions of homozygosity (ROH). However, it will not detect balanced SVs like translocations and inversions. Optical Genome Mapping (OGM) is a complementary genomic tool to sequencing, produces a genome “map” with all balanced and unbalanced SVs and CNVs circumventing the routine cytogenetics manual workflow (cell culture and karyotyping).