AGA Institute Focused Clinical Updates, May 21 and 22, 2006 To claim CME credit you must have Internet access and allow pop-up windows. Please CLICK HERE to claim CME. 22 Barrett’s Esophagus Yvonne Romero, MD Mayo College of Medicine, Rochester, Minnesota Dr. Romero is Assistant Professor of Medicine at the Mayo College of Medicine in Rochester, Minnesota. She received her MD degree from the University of Nevada School of Medicine. She completed her Internal Medicine residency training at Indiana University Medical Center in Indianapolis, Indiana, under the mentorship of Glen Lehman, M.D. Dr. Romero then traveled to the Mayo Clinic in Scottsdale, Arizona, for her first year of gastroenterology fellowship training, completing the final two years at the Mayo Clinic under the mentorship of Alan Cameron, M.D. Upon graduation, Dr. Romero trained in clinical epidemiology and biostatistics at McMaster University in Hamilton, Ontario, Canada. She returned to the Mayo Clinic for her advanced fellowship in Diseases of the Esophagus, where she remains on staff. She holds joint appointments in the Department of Otolaryngology and Department of Epidemiology and continues her education in genetic epidemiology and tumor genetics under the mentorship of Gloria M. Petersen, Ph.D. She has many publications in the area of Barrett’s esophagus and several funded research trials in the area of the genetics of familial Barrett’s esophagus, outcomes of steroid injection for distal esophageal peptic strictures, supraesophageal reflux disease, and validation of symptom questionnaires for use in research. Good morning everyone. Welcome to the Focused Clinical Update on Barrett’s Esophagus. One of the privileges of presenting the highest ranking abstracts to you is that I am permitted to review the scores of all of the Barrett’s abstracts. Those scores guided the selection of the six basic science and six clinical research abstracts we are going to discuss today. Abstract 224235 : “Evidence from linkage analysis for susceptibility genes in familial Barrett’s esophagus and esophageal adenocarcinoma” I would like to disclose that this is work was done by my team with the aid of Gloria Petersen, a genetic epidemiologist. Obviously, I feel guilty discussing it at all, but I am presenting it first because it ranked highest among this year’s abstracts. Our aim was to map susceptibility loci in familial Barrett’s esophagus by performing linkage analysis on families with the following phenotypes: GERD symptoms, hiatal hernia, reflux esophagitis, biopsy-proven Barrett’s esophagus and esophageal adenocarcinoma. Families seen at the Mayo Clinic or referred to our group with more than two family members with long segment Barrett’s esophagus, with or without cancer, were asked to participate. The index patients, known as probands, provided pedigree and contact information to enable our team to contact their relatives directly. All family members were invited to complete a validated symptom questionnaire and medical release form. Their endoscopy and/or surgical reports, and original pathology slides were reviewed. In families documented to have more than one affected member, blood was sampled to perform genotyping. Of 466 potential families that have come to our attention so far, 94 have met strict criteria to be considered Barrett’s families. The results presented in today’s abstract uses 31 of the 94 families. The goal of linkage analysis is to associate a genetic marker with a particular phenotype (e.g., Barrett’s esophagus). In linkage analysis, you genotype all affected family members. By performing a linkage analysis, we are assessing the co-transmission of a marker with a particular phenotype. The results of linkage analyses are expressed as logarithm of the odds scores, or LOD scores. Heterogeneity LOD scores, (or HLOD) scores, take into account variations among different families. Different genes will be more important in different families. If the LOD score is 2, that implies that the