title: Dizygotic Twins Concordant for Down Syndrome: Implication for Establishing a National Birth Defect Registry in Iran.
authors.affiliation: Dept. of Medical Genetics, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Shahram
authors.initials: S
authors.lastname: Savad
authors.affiliation: Dept. of Medical Genetics, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Sepideh
authors.initials: S
authors.lastname: Hamzehlou
authors.affiliation: Dept. of Obstetrics and Gynecology, Kamali Hospital, Alborz University of Medical Sciences, Karaj, Iran.
authors.forename: Jila
authors.initials: J
authors.lastname: Ghaffourian Abadi
authors.affiliation: Dept. of Medical Genetics, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammad Hossein
authors.initials: MH
authors.lastname: Modarressi
authors.affiliation: Dept. of Pediatric Endocrinology and Metabolism, Bahonar Hospital, Alborz University of Medical Sciences, Karaj, Iran.
authors.forename: Shahab
authors.initials: S
authors.lastname: Noorian