On-line version ISSN 2078-5151
S. Afr. j. surg. vol.46 n.3 Cape Town Aug. 2008
S. B. IbirogbaI; U. AlgarII; P. A. GoldbergIII; M. DuffieldIV; A. VorsterV; R. RamesaarVI
IM.B. B.S., F.C.S. (S.A.); Colorectal Unit, Department of Surgery, Groote Schuur Hospital and University of Cape Town
IIM.SC. (NURSING); Colorectal Unit, Department of Surgery, Groote Schuur Hospital and University of Cape Town
IIIM.B. CH.B., F.C.S. (S.A.), M.MED. (SURG.); Colorectal Unit, Department of Surgery, Groote Schuur Hospital and University of Cape Town
IVM.B. CH.B., L.R.C.P., M.R.C. (PATH.), F.S. (EDIN/GLASGOW), M.MED. (ANAT. PATH.); Division of Anatomical Pathology, Groote Schuur Hospital and University of Cape Town
VM.SC; Division of Human Genetics, Groote Schuur Hospital and University of Cape Town
VIPH.D; Division of Human Genetics, Groote Schuur Hospital and University of Cape Town
BACKGROUD: Hereditary mixed polyposis syndrome is characterised by multiple large-bowel polyps of differing histological types including a mixture of atypical juvenile polyps, hyperplastic polyps and adenomas. Affected individuals are thought to have an increased risk of malignancy, possibly via the juvenile polyposis pathway.
METHODS: A 51-year-old woman (with a history of a colectomy for polyps during childhood) presented with rectal bleeding. Endoscopy demonstrated small rectal polyps which were hyperplastic on histology. A family tree was drawn up and the three children of the proband underwent flexible sigmoidoscopy.
RESULTS: Endoscopic surveillance of the three children revealed one who had a similar phenotype to the mother. This child underwent colectomy and ileorectal anastomosis. The pathological specimen revealed more than 70 polyps, with a combination of juvenile retention, hyperplastic, adenomatous and inflammatory polyps. A second child had multiple small hyperplastic polyps, and the third had a normal colon. Although the gene locus for the disorder has been mapped, neither the gene nor the disease-causing mutation has been defined.
CONCLUSION: A rare inherited polyposis syndrome has been identified in a South African family. Where clinical suspicion of a possible inherited condition exists, investigating at-risk first-degree relatives confirms the inherited nature of the disease. It is possible to use genetic haplotyping (i.e. with a range of markers in the area of the gene) to provide statistical risk to immediate relatives and therefore those at highest risk.
“Full text available only in PDF format”
1. Whitelaw SC, Murday VA, Tomlinson IPM, et al. Clinical and molecular features of the hereditary mixed polyposis syndrome. Gastroenterology 1997; 112:327-334. [ Links ]
2. Murday V, Slack J. Inherited disorders associated with colorectal cancer. Cancer Surv 1989; 8: 139-157. [ Links ]
3. Jaeger EEM, Woodford-Richins KL, Lockett M, et al. Ancestry Ashkenazi haplotype at the HMPS/CRAC I Locus on 15q 13-q 14 is associated with hereditary mixed polyposis syndrome. Am J Human Genet 2003; 72: 1261-1267. [ Links ]
4. Peng H, Cao X, Li HH, et al. Haplotype and linkage analysis in Chinese hereditary mixed polyposis syndrome. Zhongha Wei Chang Wai Ke Za Zin 2005; 8(4): 312-315. [ Links ]
5. Tomlinson I, Nazneen R, Ian F, et al. Inherited susceptibility to colorectal adenomas and carcinomas. Evidence for new predisposition gene on 15q14-q22. Gastroenterology 1999; 116: 789-795. [ Links ]
6. X Cao, Kw Eu, Kumarasinghe MP, et al. Mapping of hereditary mixed polyposis syndrome (HMPS) to chromosome 10q23 by genomewide high density single nucleotide polymorphism (SNP) SCAN and identification of BMPRIA loss of function. J Med Genet 2006; 43(3): e13. [ Links ]