Symptom-conditioned prediction of comorbidity in the hEDS–POTS–MCAS triad

Bayesian hierarchical meta-analysis of published evidence examining comorbidity within the hypermobile Ehlers-Danlos syndrome (hEDS), postural orthostatic tachycardia syndrome (POTS), and mast cell activation syndrome (MCAS) triad. Using aggregate cohort data from 22 published studies, this work estimates directed comorbidity probabilities, evaluates symptom-conditioned prediction using Bayesian updating, introduces a feasibility screen based on the Fréchet–Hoeffding bounds to assess coherence of pooled evidence, and examines the identifiability of latent disease structure under disease-selected sampling. The manuscript is provided as a research preprint.