Focal cortical dysplasia, microcephaly and epilepsy in a boy with 1q21.1-q21.3 duplication

Abstract The recent advance of new molecular technologies like array – Comparative Genomic Hybridization has fostered the detection of genomic imbalances in subjects with intellectual disability, epilepsy, and/or congenital anomalies. Though some of the rearrangements are relatively frequent, their consequences on phenotypes can be strongly variable. We report on a boy harbouring a de novo 8.3 Mb duplication of chromosome 1q21.1-q21.3 whose complex unusual phenotype deserves attention, due to the presence of focal cortical dysplasia, microcephaly, and epilepsy. Loss-of-function (LOF) effects of genes associated with human disease involved in the rearrangement have been only partially established, and have not been previously associated with brain malformations in several deletion syndromes. Less is known, instead, about the consequences of their duplication on neuronal migration and brain development process. Further advance in neuroimaging and genetic research will help in defining their actual role in neurodevelopment and cerebral cortex malformations.