The AAPC case, with an early onset of colorectal cancer.
BACKGROUND
Attenuated adenomatous polyposis coli (AAPC) is a variant of the familial adenomatous polyposis (FAP) characterized by the occurrence of sparse polyps in the colon, stomach, and duodenum with a late onset of colorectal cancer. The AAPC syndrome is associated with mutations at the 5' region of the APC gene. Until recently, the fragment encompassing codons 157 and 170 was considered as boundary for the described cases of AAPC and FAP syndromes.


METHODS
This study describes a case of the AAPC syndrome caused by a CCTT deletion at codon 173, with polyps diagnosed at the age of 17. The father and grandfather of the proband died of colorectal cancer (CRC), which developed from untreated polyps, at the age 35 and 40, respectively.


CONCLUSIONS
In the case of the proband's father, the untreated polyps led to death after 12 years. The proband revealed a low number of polyps and an extra colon feature characteristic of AAPC, but the polyps onset and the death of CRC of two family members, who refused colectomy, was very early and characteristic for FAP. An atypical course of AAPC must be taken into consideration both in genetic counseling and in qualifying the patients with AAPC for the surgical treatment.
Plawski
A
A
Institute of Human Genetics, Polish Academy of Sciences, Strzeszynska, 32, 60-479 Poznan, Poland. andp@man.poznan.pl
Nowakowska
D
D
Podralska
M
M
Lipinski
D
D
Steffen
J
J
Slomski
R
R
D011125:Adenomatous Polyposis Coli / Q000209:etiology* / Q000235:genetics; D000293:Adolescent; D000328:Adult; D015179:Colorectal Neoplasms / Q000209:etiology* / Q000235:genetics; D005192:Family Health; D017809:Fatal Outcome; D016368:Frameshift Mutation; D017491:Genes, APC; D006801:Humans; D008297:Male; D010375:Pedigree; D011127:Polyps / Q000150:complications / Q000235:genetics*; D017384:Sequence Deletion