PHENOTYPIC VARIABILITY IN TOWNES-BROCKS S YNDROME

Background. - Townes-Brocks syndrome (TBS) is a rare autosomal dominan t entity mainly characterized by ano-rectal, ear and extremities abnor malities whith variable clinical expression. Case reports. - The first case had ear and extremities, bur not anorectal, abnormalities; a Pie rre-Robin sequence with esophageal atresia was also observed. The seco nd case had the classical triad of abnormalities also associated with tetralogy of Fallot wich has been only once reported in the literature . Conclusions. - Both cases are other examples of the frequent clinica l variability observed in this syndrome explaining diagnostic difficul ties in the absence of a specific marker.