BHLHA9 and sirenomelia: The London Medical Database has following entities listed with exstrophy of cloaca: caudal duplication syndrome; caudal regression; diphallus plus; femoral duplication; frontonasal dysplasia-exstrophy of bladder or cloaca; Gollop-Wolfgang complex caused by BHLHA9; sirenomelia; urorectal septal defects and VATER association.