Microdeletion syndrome

Microdeletion syndrome is a syndrome caused by a chromosomal deletion smaller than 5 million base pairs (5 Mb) spanning several genes that is too small to be detected by conventional cytogenetic methods or high resolution karyotyping (2-5 Mb). Detection is done by fluorescence in situ hybridization (FISH). Larger chromosomal deletion syndromes are detectable using karyotyping techniques