title: Multiple jejunal cancers resulting from combination of germline APC and MLH1 mutations.
abstract: Double heterozygotes for mutations in APC and a DNA mismatch repair gene are extremely rare. We report on an individual who had truncating mutations in APC and MLH1 whose clinical presentation initially resembled Familial Adenomatous Polyposis but then emerged as a novel phenotype with multiple jejunal carcinomas. We have reviewed the relevant literature on double heterozygotes and based on what has been reported to date, this phenotype was not anticipated. It may be useful for clinicians to be aware of this observation as clinical screening guidelines are proposed for such individuals.
authors.affiliation: Department of Health Science Research, Mayo Clinic Arizona, 13400 E. Scottsdale Blvd, Scottsdale, AZ 85259, USA. nlindor@mayo.edu
authors.forename: Noralane M
authors.initials: NM
authors.lastname: Lindor
authors.forename: Tom C
authors.initials: TC
authors.lastname: Smyrk
authors.forename: Sheila
authors.initials: S
authors.lastname: Buehler
authors.forename: Shanaka R
authors.initials: SR
authors.lastname: Gunawardena
authors.forename: Brittany C
authors.initials: BC
authors.lastname: Thomas
authors.forename: Paul
authors.initials: P
authors.lastname: Limburg
authors.forename: Salman
authors.initials: S
authors.lastname: Kirmani
authors.forename: Stephen N
authors.initials: SN
authors.lastname: Thibodeau
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics*; D025601:Adenomatous Polyposis Coli Protein / Q000235:genetics*; D018095:Germ-Line Mutation / Q000235:genetics*; D006801:Humans; D007580:Jejunal Neoplasms / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D000070957:MutL Protein Homolog 1; D009687:Nuclear Proteins / Q000235:genetics*; D011379:Prognosis
chemical_list: C555337:APC protein, human; D048868:Adaptor Proteins, Signal Transducing; D025601:Adenomatous Polyposis Coli Protein; C501486:MLH1 protein, human; D009687:Nuclear Proteins; D000070957:MutL Protein Homolog 1