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Y L Wallis

Publications and source records attributed to Y L Wallis.

3 recordsLinked to original sources

Molecular analysis of the APC gene in 205 families: extended genotype-phenotype correlations in FAP and evidence for the role of APC amino acid changes in colorectal cancer predisposition.

BACKGROUND/AIMS: The development of colorectal cancer and a variable range of extracolonic manifestations in familial adenomatous polyposis (FAP) is the result of the dominant inheritance of adenomatous polyposis coli (APC) gene mutations. In this study, direct mutation analysis of the APC gene was performed to determine genotype-phenotype correlations for nine extracolonic manifestations and to investigate the incidence of APC mutations in non-FAP colorectal cancer. METHODS: The APC gene was analysed in 190 unrelated FAP and 15 non-FAP colorectal cancer patients using denaturing gradient gel electrophoresis, the protein truncation test, and direct sequencing. RESULTS: Chain terminating signals were only identified in patients belonging to the FAP group (105 patients). Amino acid changes were identified in four patients, three of whom belonged to the non-FAP group of colorectal cancer patients. Genotype-phenotype correlations identified significant differences in the nature of certain extracolonic manifestations in FAP patients belonging to three mutation subgroups. CONCLUSIONS: Extended genotype-phenotype correlations made in this study may have the potential to determine the most appropriate surveillance and prophylactic treatment regimens for those patients with mutations associated with life threatening conditions. This study also provided evidence for the pathological nature of amino acid changes in APC associated with both FAP and non-FAP colorectal cancer patients.

Adenomatous Polyposis Coli↗

Genotype-phenotype correlation between position of constitutional APC gene mutation and CHRPE expression in familial adenomatous polyposis.

Mutations in the adenomatous polyposis coli (APC) gene are responsible for the disease familial adenomatous polyposis (FAP), a dominantly inherited predisposition to colorectal cancer. The most common extra-colonic manifestation is congenital hypertrophy of the retinal pigment epithelium (CHRPE), expressed in up to 90% of FAP kindreds. Chain-terminating APC mutations were characterised in 26 unrelated FAP patients. Results show that CHRPE expression is determined by the length of truncated protein product. CHRPE is therefore the first extracolonic manifestation of FAP to be shown to be under the control of the APC mutation site and should facilitate the detection of constitutional APC mutations in FAP kindreds.

Adenomatous Polyposis Coli↗