Marker chromosome (mar) is a structurally abnormal chromosome that can not be identified with conventional cytogenetic techniques (ISCN, 2005).1 The incidence of supernumerary marker chromosomes (SMCs)found at prenatal diagnosis varies from 0.4/1000 to 1.5/1000.2-5 Their genetic effects may range from harmless to detrimental, and in de novo cases, the rate of phenotypic abnormalities is statistically increased.5 Therefore, identification of SMCs has become imperative in prenatal diagnosis.