Vol. 184, No. 3, 1992 May 15, 1992 BIOCHEMICAL AND BIOPHYSICAL RESEARCHCOMMUNICATIONS Pages ]357-]363 FAMILIAL ADENOMATOUS POLYPOSIS: IDENTIFICATION OF A NEW FRAMESHIFT MUTATION OF THE APC GENE IN AN ITALIAN FAMILY Alessandro Stella^°,Angelo Lonoce ~ , Nicoletta Resta ^ , Mattia Gentile °, Francesco Susca^,Cristina Mareni§, Giuseppina Brescia ^ , Paola Origoni §, Maria Pina Montero §, and Ginevra Guanti ~* ^Institute of Genetics, University of Bari, Via Amendola 165 A, 70126 Bari Italy °IRCCS De Bellis,Castellana Grotte Italy §Dept of Internal Medicine, Via Benedetto XV,6 16132 Genova Italy Received March 26, 1992 Summary: Familial Adenoma£ous Polyposis (FAP) is a premalignant disease of the gastrointestinal tract inherited as an autosomal dominant trait assigned to chromosome 5q21. The 15 exons of the APC gene responsible for the defect were amplified from the DNA of one FAP patient. SSCP analysis of the amplified DNA revealed a variant conformer of exon i0. The sequencing of the cloned PCR product showed a 1 base insertion at position 1370, creating a stop codon four nucleotides downstream. SSCP analysis of 20 family members and nucleotide sequencing of exon i0 in three affected members confirmed the Mendelian inheritance of the mutant allele. © 1992 Academic Press, Inc. Familial adenomatous polyposis (FAP) is a premalignant disease of the gastrointestinal tract inherited as an autosomal dominant trait. The age of onset and clinical presentation of the first symptoms of the disease are variable. Without a definitive marker for the defect, offspring and siblings at risk cannot be diagnosed as affected until multiple adenomas are detected in the colorectum. These polyps, which usually exceed 500 in number * To whom correspondence should be addressed. Abbreviations:FAP,familial adenomatous polyposis;APC,adenomatous polyposis coli;SSCP,single strand conformation polymorphism;TBE buffer, 89mM Tris, 89mM boric acid, pH 8.3 and 2mM EDTA ; RFLP, restriction fragment lenght polymorphism; GS,Gardner's syndrome;PCR,polymerase chain reaction. 1357 0006-291X/92 $4.00 Copyright © 1992 by Academic Press, Inc. All rights of reproduction in any form reserved.