IGFBP2 and congenital heart disease: Among the 37 fetuses with the 15q11.2 BP1-BP2 microdeletion syndrome, 25 showed phenotypic abnormalities on intrauterine ultrasound (67.6%), among which the most common ultrasonic structural abnormality was congenital heart disease (five cases; 13.5%), followed by renal dysplasia and Dandy-Walker malformation in one case each.