INTRODUCTION The impact of Scheuermann’s disease (SD) on health-related quality of life (HRQoL) is unclear. Our aim was to study HRQoL based on The Medical Outcome Study Short Form-12 (SF-12) in adult life in a group of SD patients. MATERIAL AND METHODS 75.3% of 46,418 twins answered a questionnaire which included questions from the SF-12. We compared SF-12 values in SD patients and control patients, identified 259 “non-concordant” twin pairs, and compared SF-12 values from the SD twin and the healthy twin. RESULTS SD was identified in 943 persons, leaving 33,064 persons in the control g...