Exostoses, Multiple, Type Ii, also known as exostoses, multiple, type 2, is related to seizures, scoliosis, and macrocephaly/microcephaly syndrome and exostoses, multiple, type i. An important gene associated with Exostoses, Multiple, Type Ii is EXT2 (Exostosin Glycosyltransferase 2). Affiliated tissues include bone and breast, and related phenotypes are multiple exostoses and chondrosarcoma