Purpose: The chromodomain helicase DNA-binding (CHD) protein family comprises adenosine triphosphate-dependent chromatin remodelers that regulate chromatin structure and gene expression. Pathogenic CHD2 variants are associated with neurodevelopmental phenotypes, but these genotype–phenotype correlations remain unclear. This study aimed to delineate the clinical and genetic features of patients with CHD2-related disorders and to explore the associated genotype–phenotype relationships. Methods: Among 22 patients with pathogenic or likely pathogenic CHD2 variants identified using a customized 172-gene neurodevelopmental and epilepsy panel, 19 with sufficient clinical data were included. Demographic, clinical, neuroimaging, electroencephalographic, and genetic data were retrospectively reviewed. Results: Eighteen pathogenic or likely pathogenic variants were identified, including eight novel variants: nine nonsense (50.0%), five splice-site (27.8%), two missense (11.1%), and two exon deletions (11.1%). All patients had epilepsy, with a median age of seizure onset of 2.33 years. Comorbidities included global developmental delay (89.5%), intellectual disability (82.0%), and neuropsychiatric symptoms (47.4%). Seizure types were heterogeneous, with a predominance of generalized-onset seizures, and 13 patients (68.4%) achieved seizure freedom. Marked phenotypic variability was observed: two unrelated patients with the same truncating variant had different developmental and seizure-related profiles, a symptomatic child with an inherited exon 5 deletion contrasted with her asymptomatic father, and a patient with an exon 17–29 deletion exhibited relatively mild features. Conclusion Epilepsy was a consistent manifestation in this study and was accompanied by diverse developmental and neurobehavioral features, with substantial genotype–phenotype discordance. Further research on genotype–phenotype correlation is warranted.

Purpose: Brain magnetic resonance imaging (MRI) is commonly performed to exclude secondary causes of pediatric headache. Incidental findings are detected in approximately one-fifth of scans, and nonspecific white matter lesions (WMLs) have been reported in 0.7% to 47% of pediatric patients with headache. However, the natural history of these lesions remains unclear. This study aimed to determine the prevalence and radiologic course of WMLs in pediatric patients with headache. Methods: We retrospectively reviewed the clinical and MRI data of pediatric patients who underwent brain MRI for headache at a single tertiary-care center between September 2006 and July 2023. Patients with neurological or systemic conditions known to cause WMLs were excluded. MRI findings and clinical characteristics were analyzed descriptively. Results: Among the 515 enrolled patients (mean age, 10.7 years), abnormal MRI findings were observed in 126 (24.5%), including nonspecific WMLs in eight (1.6%). Most lesions were supratentorial (seven of eight), with a mean maximum diameter of 10.0 mm (range, 4.3 to 24.9). Follow-up MRI was available for three patients; two demonstrated interval increases in lesion extent on repeat imaging. During the same period, headache frequency or severity also increased, but no new neurological deficits were documented. Conclusion Nonspecific WMLs were rare in pediatric patients with headache. In a small subset with limited follow-up, interval radiologic changes were observed without neurological deterioration. Larger prospective studies are needed to clarify the natural history and clinical significance of WMLs in pediatric headache.

Purpose: Autism spectrum disorder (ASD) exhibits heterogeneous developmental trajectories; however, longitudinal studies using the Korean Childhood Autism Rating Scale (K-CARS) are scarce. This study examined diagnostic changes and related developmental characteristics through repeated K-CARS assessments. Methods: We retrospectively reviewed the medical records of children who underwent repeated K-CARS assessments between May 2021 and December 2024 at Gyeongsang National University Hospital. Based on diagnostic status at the initial (T1) and follow-up (T2) evaluations, participants were classified as having persistent ASD (ASD at T1 and T2), emerging ASD (non-ASD at T1 but ASD at T2), or desisting ASD (ASD at T1 but non-ASD at T2). Developmental profiles were evaluated using the social quotient (SQ), visual-motor integration (VMI), and language quotients. Results: Forty-three children (32 boys; median age, 2.9 years at T1 and 4.3 years at T2) were included. Twenty-two met ASD criteria at T1, and 15 (68%) retained the diagnosis at T2. Across the cohort, 15 (35%) had persistent ASD, 21 (49%) had emerging ASD, and seven (16%) had desisting ASD. The desisting group showed higher baseline VMI and better outcomes at follow-up. The emerging group initially had higher SQ and VMI than the persistent group, but these differences disappeared over time. Higher baseline VMI was associated with desisting status and higher baseline SQ with emerging ASD (odds ratios, 3.14 and 2.59 per standard deviation increase, respectively; P=0.06 and P=0.07). Conclusion Early ASD diagnoses were generally stable yet variable, supporting repeated assessment. Baseline VMI and SQ may relate to later diagnostic changes.

Purpose: Exanthem subitum (ES), most commonly caused by human herpesvirus 6B (HHV-6B), is a prevalent febrile illness in infants and toddlers. Previous studies have suggested a possible association between HHV-6B infection and an increased risk of complex febrile seizures (CFS). Given that CFS may prompt additional diagnostic procedures to rule out serious neurological disorders, we compared the clinical characteristics and management of patients with and without ES. Methods: We retrospectively reviewed the medical records of 141 children younger than two years of age who experienced their first febrile seizure between March 2013 and August 2024 at a tertiary medical center. We collected demographic, clinical, and laboratory data and compared clinical profiles between children diagnosed with ES and those without ES. Results: Twenty-eight children (19.9%) were clinically diagnosed with ES. Although the frequency of CFS did not significantly differ between the ES and non-ES groups (42.9% vs. 28.3%, P=0.172), children with ES were more likely to undergo lumbar puncture (42.9% vs. 11.5%, P<0.001) and receive empiric intravenous antibiotics for suspected central nervous system infection (39.3% vs. 10.6%, P<0.001). Conclusion Despite the typically benign and self-limiting nature of ES, febrile seizures occurring in the context of ES appear to be associated with more aggressive diagnostic and therapeutic interventions. The development of rapid, noninvasive diagnostic assays for HHV-6B may help reduce unnecessary procedures and promote more judicious management.

Purpose: Preterm birth remains a leading cause of long-term neurodevelopmental impairment, yet early evaluations frequently underestimate subsequent deficits. This study examined longitudinal neurodevelopmental trajectories across gestational age groups and identified predictors of developmental delay. Methods: A retrospective cohort of 532 preterm children, stratified by gestational age, was followed from the neonatal period to early preschool age. Neurodevelopment was assessed using the Korean version of the Bayley Scales of Infant and Toddler Development, Third Edition at 8–12 months (n=481), 13–24 months (n=118), and 25–42 months (n=100). Longitudinal trajectories were analyzed using general linear models, and predictors of developmental delay were identified through multivariable logistic regression. Results: During the first year, motor scores differed significantly across gestational age groups, with extremely preterm infants showing the lowest values. By the third to fourth years of life, cognitive and language scores diverged markedly, with extremely preterm children exhibiting the steepest decline and additional deficits in motor and adaptive behavior domains. Lower gestational age remained an independent predictor of both cognitive and language delay at early preschool age, while no independent predictors were identified for motor, social-emotional, or adaptive behavior outcomes. Conclusion Neurodevelopmental outcomes in preterm children follow dynamic, domain-specific trajectories influenced by gestational age and developmental timing. Motor delays are most evident in infancy, whereas cognitive and language impairments emerge by early preschool age. Gestational age remains a consistent predictor of later delay, emphasizing the need for longitudinal, gestational age–stratified monitoring and early, targeted intervention.