Multiple jejunal cancers resulting from combination of germline APC and MLH1 mutations

• Published in: Familial cancer Vol. 11; no. 4; pp. 667 - 669
• Main Authors: Lindor, Noralane M., Smyrk, Tom C., Buehler, Sheila, Gunawardena, Shanaka R., Thomas, Brittany C., Limburg, Paul, Kirmani, Salman, Thibodeau, Stephen N.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-12-2012; Springer Nature B.V
• Subjects: Adaptor Proteins, Signal Transducing - genetics; Adenomatous Polyposis Coli Protein - genetics; Biomedical and Life Sciences; Biomedicine; Cancer Research; Epidemiology; Germ-Line Mutation - genetics; Human Genetics; Humans; Jejunal Neoplasms - genetics; Male; Middle Aged; MutL Protein Homolog 1; Nuclear Proteins - genetics; Prognosis; Short Communication; Familial Adenomatous Polyposis; Jejunum; Lynch Syndrome; Double heterozygote
• ISSN: 1389-9600; 1573-7292
• DOI: 10.1007/s10689-012-9561-3

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.