# Contrasting Relationships Between Anxiety and Intolerance of Uncertainty in Cornelia de Lange and Fragile X Syndromes

## TL;DR

This study explores how anxiety and intolerance of uncertainty relate in two genetic syndromes, finding differences that suggest the need for syndrome-specific approaches.

## Contribution

The study reveals that intolerance of uncertainty mediates anxiety in Cornelia de Lange syndrome but not in fragile X syndrome.

## Key findings

- Intolerance of uncertainty mediates the autism-anxiety relationship in Cornelia de Lange syndrome.
- This mediation effect is not observed in fragile X syndrome.
- The findings suggest syndrome-specific factors influence anxiety in these genetic conditions.

## Abstract

Cornelia de Lange syndrome (CdLS) and fragile X syndrome (FXS) are associated with co‐occurring autism and anxiety. In autistic people, intolerance of uncertainty (IU) mediates the relationship between autistic characteristics and anxiety, but it is not known whether this relationship is evident in these genetic syndromes. Understanding the relationship between autism, anxiety and IU is essential to informing the theoretical frameworks of anxiety in rare genetic syndromes and improving clinical interventions.

Sixty participants with CdLS or FXS participated in a questionnaire‐based study to examine the association between autistic characteristics, anxiety and IU.

IU mediated the association between autism and anxiety in participants with CdLS but not in participants with FXS.

These results suggest that other factors may contribute to the autism‐anxiety relationship in FXS, and highlight the merit of syndrome‐specific approaches to the study of anxiety. Recommendations are made for intervention‐based research to ameliorate anxiety in CdLS.