PT - JOURNAL ARTICLE AU - Grobbelaar, J J AU - Ziskind, A AU - de Jong, G AU - Oosthuizen, C J AU - Kotze, M J TI - A novel deletion at codon 441 of the APC gene associated with ophthalmic lesions (CHRPE) in a South African family. AID - 10.1136/jmg.33.5.384 DP - 1996 May 01 TA - Journal of Medical Genetics PG - 384--386 VI - 33 IP - 5 4099 - http://jmg.bmj.com/content/33/5/384.short 4100 - http://jmg.bmj.com/content/33/5/384.full SO - J Med Genet1996 May 01; 33 AB - A novel mutation at codon 441 in exon 10 of the adenomatous polyposis coli (APC) gene was identified in a South African family of mixed ancestry, using a convenient, non-radioactive, heteroduplex-SSCP screening assay. This single thymidine deletion after nucleotide position 1322 creates a frameshift resulting in a downstream stop codon at amino acid residue 453 of the APC gene. Genotypes of nine family members were subsequently correlated with the presence or absence of congenital hypertrophy of the retinal pigment epithelium (CHRPE), since expression of this common extracolonic manifestation of FAP is largely determined by the length of the truncated protein. CHRPE was absent in the five unaffected family members analysed, while four mutation positive subjects showed these ophthalmic lesions. Correlation between the molecular analysis and ophthalmic examinations, performed without knowledge of clinical and genetic status respectively, provided additional evidence in favour of the view that the range of phenotypic expression in FAP may result from different allelic manifestations of APC mutations.