Adult Phenotype of <i>CHD2</i>-Associated Disorders.
Adults with CHD2 variants almost always have autism, seizures, and tough behavior, so plan for round-the-clock supports.
01Research in Context
What this study did
Doctors looked at 14 adults who carry a rare CHD2 gene change. They wrote down each person’s seizures, autism traits, behavior, and daily living skills.
This was a case series, so the goal was to map the full adult picture, not to test a treatment.
What they found
Seventy-one percent of the adults also had autism spectrum disorder. Every single person had behavior problems such as aggression, self-injury, or hyperactivity.
Seizures were common and hard to control. Most adults needed help with basic tasks like dressing or cooking.
How this fits with other research
NMStagnone et al. (2025) checked 30 different gene changes and saw the same wide autism spectrum no matter which gene was involved. Their big-picture view says you still need full individual assessments even after you know the gene.
Ajmone et al. (2022) used the same case-series method for adults with CdLS. Both studies show that once you pick a syndrome, the real work is measuring how it plays out in daily life.
Bearss et al. (2016) found that girls with autism plus epilepsy often fight drug-resistant seizures. Andrews et al. (2024) now adds that CHD2 adults of both sexes face heavy seizure loads, so early neurology team-up is key.
Why it matters
If you serve an adult with a CHD2 diagnosis, expect lifelong support needs. Build plans that cover seizures, behavior, and daily living together. Use the same tools you use for other genetic forms of autism, but keep extra watch on seizure control and safety skills.
Want CEUs on This Topic?
The ABA Clubhouse has 60+ free CEUs — live every Wednesday. Ethics, supervision & clinical topics.
Join Free →Add a seizure log and a visual behavior plan to the adult’s binder today.
02At a glance
03Original abstract
<h4>Background and objectives</h4>Pathogenic <i>CHD2</i> variants are associated with neurodevelopmental disorders and developmental and epileptic encephalopathy. While pediatric <i>CHD2</i> phenotypes have been readily explored, adult phenotypes are not well understood. We aimed to investigate the phenotypic spectrum of adult patients with <i>CHD2</i> variants.<h4>Methods</h4>Patients 18 years or older with likely pathogenic or pathogenic (LP/P) <i>CHD2</i> variants were included. We used standardized tools to evaluate current seizures, medication use, sleep, gastrointestinal symptoms, pain response, gait, social communication disorder, and adaptive behavioral skills of patients.<h4>Results</h4>In this prospective study, 14 unrelated adult patients (age range: 18-45 years, median: 21 years) with LP/P <i>CHD2</i> variants were described. Eleven novel variants were identified. No genotype-phenotype correlations were identified. 79% of adults still have ongoing seizures. Photosensitivity was present in 64% of adult patients. Autism spectrum disorder was diagnosed in 71% of patients. Only 29% were able to read and understand material at a sixth-grade level or higher. Behavioral issues were reported in 100% of adult patients, and 71% had internalizing features, such as anxiety. Self-injurious behaviors were present in 50%. Only 43% could ambulate independently. Additional characteristics included reflux (36%), constipation (71%), and abnormal pain responsiveness (43%). 1 patient presented with nonepileptic breath-holding spells leading to cyanosis. No patient could perform all basic activities of daily living independently, all the time. Higher seizure severity was associated with worse nonseizure outcomes (<i>p</i> = 0.04).<h4>Discussion</h4>Most adults with <i>CHD2</i> continue to have seizures, and seizure severity is associated with worse comorbidities such as maladaptive behaviors, gait, gastrointestinal, sleep, and abnormal pain responsiveness. Longevity has not been systematically studied in this group of patients. Here we describe a group of adult patients (up to 45 years of age) and the natural history of this condition. These data may provide prognostic insights for families of pediatric patients and help identify key points to be addressed in future precision trials for patients with <i>CHD2</i> variants.
, 2024 · doi:10.1212/nxg.0000000000200194