Familial adenomatous polyposis: desmoid tumours and lack of ophthalmic lesions (CHRPE) associated with APC mutations beyond codon 1444

Abstract

An earlier study has shown that FAP patients with mutations in codons 136–302 of the APC gene do not develop congenital hypertrophy of the retinal pigment epithelium (CHRPE), whereas those with mutations in codons 463–1387 regularly do. Here we present data on 36 patients from 20 families with mutations in codons 1445–1578. These patients lack CHRPE. Furthermore, with the exception of three prepubertal children all patients with mutations in codons 1445–1578 developed desmoid tumours. This relationship between certain extracolonic manifestations and site of the APC mutation points to a specific role of the APC protein in different tissues.