Clinical characteristics and genetic analysis of children with corpus callosum abnormalities

Abnormalities of the corpus callosum (ACC) are common in pediatric populations. Classification by its morphology did not correlate well with the clinical characteristics of the patients. We aim to analyze the clinical and genetic characteristics of ACC, with categorizing them based on whether they are congenital lesions or secondary changes to other brain lesions.

This retrospective study analyzed the clinical, demographic, and genetic characteristics of 35 children and adolescents whose brain magnetic resonance imaging revealed ACC at our institution between August 2016 and July 2022. Patients were categorized into primary ACC as a congenital lesion and secondary ACC resulting from perinatal lesions, such as preterm brain injuries, ventriculomegaly or mass lesions.

Eighteen patients exhibited primary ACC, while seventeen patients exhibited secondary ACC; eleven patients (64.7%) of secondary group were associated with preterm brain injuries. The age at diagnosis for primary ACC was earlier than that for secondary ACC (0.32 ± 0.48 vs. 6.73 ± 4.95, p < 0.001). Patients with secondary ACC experienced more seizures than those with primary ACC (70.6% vs. 33.3%, p = 0.028). Minor anomalies were significantly more common in patients with primary ACC than in those with secondary ACC (61.1% vs. 23.5%, p = 0.041). Genetic tests, including karyotype, chromosomal microarray, and whole exome sequencing, were performed in 21 patients; 15 with primary ACC and 6 with secondary ACC. Genetic diagnosis was confirmed in 11 out of 21 patients who had done genetic tests, with no significant difference in diagnostic rates between the two groups.

Appropriate use of genetic studies is required in patients with both primary and secondary ACC. Seizures were more common in secondary ACC patients, and minor anomalies were more prevalent in primary ACC patients. Both groups had high rates of developmental delay or intellectual disability.