TY - JOUR AU - Leggett, B A TI - Severe upper gastrointestinal polyposis associated with sparse colonic polyposis in a familial adenomatous polyposis family with an APC mutation at codon 1520 JO - Gut IS - 04 VL - 41 PY - 1997 DO - 10.1136/gut.41.4.518 SP - 518 EP - 521 N1 - et al. ER -