Morphological Markers of Gastroesophageal Reflux Disease (GERD)

This will be a prospective case control study. Children between the ages of 8 and 18 with
suspected gastroesophageal reflux disease (GERD) or eosinophilic esophagitis (EoE) based on
symptom criteria and who have been scheduled for esophagogastroduodenoscopy (EGD) by their
primary gastroenterologist will be recruited.

Children who do not have any history of esophageal disease or esophageal symptoms and are
scheduled for EGD for other clinical indications (e.g. rule out celiac disease) by their
primary gastroenterologist will be recruited and act as controls. Control subjects will also
be given the opportunity to undergo esophageal MII-pH monitoring as part of their medical
evaluation, but will not be excluded from analysis should they opt out of this part of the
study.

For all subjects, in addition to endoscopic evaluation, biopsies of the distal esophagus
will be obtained for routine light microscopy (standard histology sample) as well as
Transmission Electron Microscopy (TEM) analysis to determine the presence and magnitude of
dilated intercellular spaces (DIS), and immunoblotting for e-cadherin cleavage

Inclusion Criteria for GERD or EoE Subjects:

- Children between the ages of 8-18 years

- Suspected diagnosis of GERD or EoE based on symptom criteria

- Able to tolerate upper endoscopy examination with biopsies

Inclusion Criteria for Control Subjects:

- Children between the ages of 8-18

- Scheduled for EGD for clinical indications

- No history of esophageal disease of esophageal symptoms

- Able to tolerate upper endoscopy examination with biopsies

Exclusion Criteria for GERD or EoE Subjects:

- History of Barrett's esophagus

- Previous esophageal or gastric surgery

- History of congenital defect/malformation of the esophagus

- Diagnosis of Crohn disease

Exclusion Criteria for Control Subjects:

- Symptoms of GERD or EoE (including heartburn, regurgitation, difficulty swallowing,
painful swallowing).