<b><i>Introduction:</i></b> Duplication of 12q is characterized by craniofacial dysmorphia, growth failure, occasional brain malformations, abnormalities of the extremities, skeletal and thoracic malformations, cardiovascular defects, anogenital abnormalities like cryptorchidism, psychomotor delay, and intellectual disability. <b><i>Case presentation:</i></b> We describe a female patient with typical manifestations of duplication 12q and epilepsy. She had a normal 46,XX karyotype. The microarray assay exhibited a 19.35-Mb gain at 12q24.21q24.33 due to ins(21;12)(p11.2;q24.21q24.33)mat. <b><i>Discussion and Conclusion:</i></b> The duplicated region in the patient encompasses 219 genes, 24 considered as pathological. No relation between epilepsy and the genes reported as pathological has been reported.