Here we report on 12 affected members of a family with Bannayan-Riley-Ruvalcaba syndrome. We present clinical evidence of overlap between Bannayan-Zonana syndrome. Riley-Smith syndrome, and Ruvalcaba-Myhre syndrome in this autosomal dominantly inherited condition. We expand the phenotypic spectrum to include Hashimoto thyroiditis, which occurred in 7 of our cases. Finally, we discuss the relationship between the syndrome and juvenile polyposis of infancy.