Cornelia de Lange syndrome (CdLS) is a rare genetic condition caused by variants affecting the cohesin complex, a group of proteins that holds chromosomes together and helps regulate which genes switch on during development. Most cases involve the NIPBL gene, with a smaller number caused by changes in SMC1A, SMC3, RAD21, or HDAC8. People with CdLS often have distinctive facial features such as long eyebrows that meet in the middle, long eyelashes, and a thin, downturned upper lip, along with small stature, limb differences ranging from small hands to missing fingers, and developmental delay or intellectual disability that varies widely from person to person. Autism-related traits, anxiety, and self-injurious behavior have long been recognized as common in CdLS, often grouped loosely under the label “autistic-like behavior.” A cluster of 2025 studies has started to pull that label apart, asking more specific questions: does anxiety in CdLS work the same way it does in autism generally, or in other genetic syndromes? And when standard tests suggest a social-understanding deficit, is that always the full picture?
What explains anxiety and autism-related traits in Cornelia de Lange syndrome?
A 2025 study published in the Journal of Intellectual Disability Research examined a specific psychological mechanism called intolerance of uncertainty (IU), a tendency to find not-knowing distressing, that is already known to help explain why autistic people experience anxiety. Researchers asked whether the same mechanism applies to CdLS, and tested it against fragile X syndrome (FXS), another genetic condition where autism and anxiety frequently co-occur. A total of 60 participants with CdLS or FXS completed questionnaires measuring autistic characteristics, anxiety, and IU. The results diverged sharply between the two syndromes: IU mediated the relationship between autism and anxiety in people with CdLS, meaning higher autistic traits were linked to more intolerance of uncertainty, which in turn was linked to more anxiety. In FXS, this pathway did not hold. The authors concluded that anxiety in these two genetic syndromes likely arises through different underlying mechanisms, even though both syndromes involve overlapping autism and anxiety traits on the surface. That distinction matters clinically: an intervention built around reducing uncertainty and increasing predictability has a clear theoretical rationale in CdLS specifically, while FXS may call for a different approach entirely.
Coping strategies for individuals and families
- Reduce uncertainty wherever practical. Because intolerance of uncertainty appears to be a specific driver of anxiety in CdLS, predictable routines, advance warning before changes, and clear visual schedules address the mechanism directly rather than just managing anxious behavior after it appears.
- Don't assume a low score on a verbal social-understanding test means someone can't understand others. Research on mentalizing in CdLS found that traditional, language-heavy tests may underestimate real social-cognitive ability. Watching how a person responds in everyday social situations, not just how they perform on formal testing, gives a fuller picture.
- Target planning, task-switching, and self-control directly, not just the behaviors they affect. Executive function difficulties have been linked to broader emotional and behavioral challenges in CdLS. Structured practice with planning tasks, visual cues for switching activities, and scaffolded self-regulation strategies work on the root skill rather than only the downstream symptom.
- Take reports of distress seriously, even when the person can't fully explain them in words. Self-injurious and reactive behaviors documented in CdLS are often responses to something happening in the body or environment rather than behavior for its own sake. Looking for triggers, pain, sensory discomfort, disrupted routine, can reveal the actual source of distress.
- Recognize that CdLS-specific anxiety may not respond to generic autism-anxiety advice. Because the study found a different anxiety pathway in CdLS compared with fragile X syndrome, approaches developed for autism in general, or for another genetic syndrome, may not transfer directly. Syndrome-specific guidance, where it exists, is worth seeking out.
A closer look: what mentalizing research reveals about Cornelia de Lange syndrome
A 2025 study in Oxford Open Neuroscience investigated whether children with CdLS truly have the social-understanding deficits that standard tests suggest, or whether the tests themselves are missing something. Mentalizing, the ability to understand that other people have their own thoughts, beliefs, and perspectives, is usually measured with explicit tasks that require a child to verbally reason about a story character's false belief. These tasks carry heavy language demands. The researchers compared performance on explicit tasks against an implicit task that simply tracked where children looked, an anticipatory-looking measure that does not require language, across four groups: children with CdLS (9), boys with fragile X syndrome (9), autistic children (22), and neurotypical children (34). Neurotypical children outperformed every other group on the explicit, language-based task, as expected. But on the implicit, language-free task, children with CdLS and FXS performed as well as neurotypical children, while autistic children lagged behind on both measures. In the CdLS and FXS groups, explicit mentalizing scores were not linked to either age or language ability, unlike in the neurotypical and autistic groups, suggesting something other than general development was limiting their explicit scores. The authors concluded that traditional, language-heavy tasks may mask real mentalizing ability in children with CdLS and FXS, a finding that pushes back against assuming low scores on a single test type reflect a child's true social-cognitive capacity.
Mental health care considerations
A third 2025 study, published in the Journal of Psychiatric Research, looked at executive function (EF) as a possible shared risk marker across different genetic syndromes rather than a syndrome-specific quirk. Researchers assessed 14 children and adolescents with CdLS and 15 with Rubinstein-Taybi syndrome (RSTS), another rare condition involving intellectual disability, using caregiver-report measures of executive function, emotional and behavioral symptoms, and autism-related traits. Across both syndromes, difficulties with inhibition, set-shifting, and planning were the strongest predictors of internalizing symptoms (such as anxiety and low mood), externalizing symptoms (such as irritability and acting out), and autism-related traits. The authors noted that this pattern mirrors research in typically developing children, where EF deficits act as a transdiagnostic risk factor cutting across multiple types of difficulty, rather than mapping onto one specific diagnosis. For clinicians, this suggests that rehabilitation programs targeting EF skills directly could reduce a wide range of emotional and behavioral symptoms simultaneously in CdLS, rather than requiring separate interventions for each symptom. The sample sizes in this study were small, as is common in rare-syndrome research, so these findings should be treated as an early and promising signal rather than a settled conclusion, with assessment and care still best delivered by clinicians experienced in CdLS specifically.
Tips for supporting someone with Cornelia de Lange syndrome
- Build predictability into daily routines. Given the specific link between intolerance of uncertainty and anxiety in CdLS, consistent schedules, advance notice of changes, and visual countdowns to transitions can reduce anxiety at its source.
- Look past formal test scores when judging social understanding. Because explicit, language-based tasks may underestimate real mentalizing ability, pay attention to how a person navigates real relationships and social situations, not just how they perform on a single verbal assessment.
- Practice executive function skills in everyday contexts. Breaking multi-step tasks into smaller steps, using visual planners, and rehearsing transitions between activities builds the inhibition, set-shifting, and planning skills linked to broader emotional wellbeing.
- Investigate the cause behind self-injury or reactive behavior rather than only managing the behavior itself. These behaviors are frequently a response to an underlying trigger, physical discomfort, sensory overload, or a disrupted routine, and addressing that trigger can be more effective than addressing the behavior alone.
- Seek out CdLS-specific resources and clinicians where possible. Because anxiety and social-cognitive challenges in CdLS may work differently than in autism generally or in other genetic syndromes, guidance developed specifically for CdLS, including through condition-specific family organizations, is likely to be more relevant than general advice.