Table 1.
Overview of the most common Hamartomatous Polyposis Syndromes
| Genes | Hallmark features | Cancer by site | Approx. mutation detection rate (%) | |
|---|---|---|---|---|
| Juvenile polyposis syndrome |
SMAD4, BMPR1A |
Multiple GI-polyps, epistaxis,* telangiectasia* |
Colon, rectum and stomach |
60% [2] |
| PTEN-hamartoma syndrome: Cowden Syndrome |
PTEN |
Lhermitte-Duclos disease, trichilemmoma, skin hamartoma, macrocephaly, |
Breast, thyroid, uterus, colon |
Up to 80% [6] |
| PTEN-hamartoma syndrome: Bannayan-Riley-Ruvalcaba |
PTEN |
Macrocephaly, lipomatosis, pigmented macules of the glans penis |
As above |
60% [7] |
| Peutz-Jeghers syndrome |
STK11 (LKB1) |
Mucocutanous melanosis and polyposis of the GI-tract |
Colon, stomach, breast, pancreas (cervix, ovarian) |
80%-94% [8] |
| Hereditary mixed polyposis syndrome | (BMPR1A, GREM1) | Atypical polyposis with juvenile polyps, adenomas, hyperplastic and inflammatory | Colon and rectum | Unknown |
*In SMAD4 mutation carriers.