Wolf-Hirschhorn Syndrome WHSC1

A 18-month-old boy born to non-consanguineous Indian parents presents with severe growth retardation, microcephaly, and recurrent seizures beginning at 14 months of age. On examination, he has a distinctive facial appearance with a high forehead, prominent glabella, hypertelorism, and a broad nose continuous with the forehead (Greek warrior helmet facies). His developmental milestones are significantly delayed. Chromosomal microarray reveals a deletion at 4p16.3 involving the region marked **A** in the diagram. Which of the following best explains the pathophysiology of seizures in this patient?