IGFBP2 and Down syndrome: The remaining 12 fetuses with the 15q11.2 BP1-BP2 microdeletion syndrome showed no abnormal phenotype in intrauterine ultrasound screening, and the indications for prenatal diagnosis in these cases were advanced age in six cases, high risk for Down syndrome in four cases, poor fertility history in one case, and family history of hemophilia in one case.