Evidence ofclonal variants ofHelicobacter pylon in three generations ofaduodenal ulcer disease family

Ninemembers ofafamily withahigh incidence ofduodenal ulcer disease werestudied by interview, examination ofhospital records, endoscopy, andantral biopsy. Helicobacter pylonwasconfirmed byCLO test, histology andculture. DNA extraction frompureisolates ofH pylori waspossible insixfamily members andstrain typing wasperformed byrestriction fragmentlengthpolymorphism. DNA restriction digestion wasfollowed byvacublotting andthenDNA hybridisation, using a cDNAprobe complimentary toHpylori rRNA cistrons. Eight oftheninefamily members wereH pylonpositive byCLO testand histology. Fivehadduodenal ulcer disease. Threefamily members (onefromeachgeneration) harboured clonal variants ofa single parent strain ofH pylonbutonlytwohad duodenal disease. Theother three members harboured different strains. Intrafamilial clustering ofclonal variants ofHpylon occurs insomeduodenal ulcerdisease families. Family membershowever, maydevelop duodenaldisease irrespecitve ofthecolonising strain. (Gut 1992; 33:1323-1327)