A Cross-Sectional Study Survey to Develop a Clinical Screen for Down Syndrome Regression Disorder in the United Kingdom.

Down syndrome regression disorder (DSRD) is marked by a sudden loss of previously acquired skills or behavior without a clear cause in individuals with Down syndrome (DS). Awareness of this condition has increased recently, with new therapeutic options under trial. The precise incidence is unknown due to confounding factors and gaps in capturing symptoms within the broader community. The application of narrower guidelines presents challenges in accurately reporting symptoms across the wider DS community. We conducted a survey across the UK based on 2022 DSRD consensus guidelines among parents and carers of children and young adults with DS, with 158 detailed responses about demographics, symptoms, and triggers. The survey revealed critical insights into the challenges faced by parents and carers. Results indicate a significant diagnostic threshold for DSRD within a symptom score range of 20.2-25.6, capturing about 80% of cases. Patients scoring above 20.2 are at high risk for DSRD from a statistical perspective. This threshold is vital for early detection and intervention, potentially improving patient outcomes. While it may overestimate diagnoses, the questionnaire serves as a screening tool for identifying those at risk.