10.1 Genetic Mutations in Mendelian Disorders Mendelian disorders are genetic diseases that show Mendelian pattern of inheritance. Traditionally, karyotyping and fluorescent in-situ hybridization (FISH) was used to identify gross genetic abnormalities while in recent years microarrays have provided better resolution. Since most of the genetic abnormalities in a number of Mendelian disorders are small (bp-kbp), HT-NGS with a single nucleotide resolution would be better suited for identifying them. Moreover, HT-NGS systems could be used to sequence the entire exome or targeted exonic regions along with the associated 5’, 3’ and intronic regions for focused genetic variation detection. Additionally, multiplexing capabilities of HT-NGS technology would allow for sequencing small regions of multiple samples in a single lane/ well. Exome sequencing has been used to identify genes underlying rare Mendelian disorders; Miller syndrome [QUERY Reference format – Author name] and Kabuki syndrome.