RT Journal Article SR Electronic T1 Monozygotic twins discordant for exstrophy of the urinary bladder. JF Journal of Medical Genetics JO J Med Genet FD BMJ Publishing Group Ltd SP 139 OP 141 DO 10.1136/jmg.18.2.139 VO 18 IS 2 A1 M Bugge YR 1981 UL http://jmg.bmj.com/content/18/2/139.abstract AB A pair of monozygotic male twins discordant for ectopia vesicae urinariae is described. There is no reason to think that any exogenic factors contributed to the aetiology. There was no consanguinity and no history of congenital anomalies on either side of the family. Published reports concerning family incidence and twin reports are reviewed.