KIT and gastrointestinal stromal tumor: The specific KIT exon 11 deletion mutation described in the first family with an identified germline mutation in familial GIST, does not seem to be required for the familial GIST syndrome as a similar clinical phenotype involving hyperpigmentation and GIST predisposition was seen in a Spanish family with an alternative exon 11 KIT mutation consisting of a duplication of the sequence CAACTT[30].