Clinical and genomic findings in brain heterotopia: Report of a pediatric patient cohort from Romania.

Brain heterotopia is a group of rare malformations with a heterogeneous phenotype, ranging from asymptomatic to a severe clinical picture (drug-resistant epilepsy, severe developmental delay). The etiology is multifactorial, including both genetic and environmental factors. In the present study, a cohort of 15 pediatric patients with brain heterotopia were investigated by clinical examination, electroencephalographic studies, brain imaging, and genomic tests. Most of the patients had epileptic seizures, often difficult to control with one antiepileptic drug; another frequent characteristic in the cohort was developmental delay or intellectual disability, in some cases associated with behavioral problems. The genomic studies revealed an interstitial 22q11.2 microduplication, an anomaly not reported previously in heterotopia patients. Comparing the cohort of the present study with that of a previous series of heterotopia patients, both adult and pediatric, similar aspects, such as the high frequency of drug-resistant epilepsy were observed as well as some differences, such as no systemic malformations and no cases with fatal evolution. The current findings add new data to existing knowledge on a rare heterogeneous disorder. The detailed clinical description, including the epilepsy phenotypes, and genomic profiles bring new insights into a group of disorders, yet to be fully understood.