DYRK1A and Down syndrome: Dual-specificity tyrosine-phosphorylation regulated kinase 1A (DYRK1A), which is involved in neurodevelopment, is repressed by the AP4-Gem complex, but, in the fetal brain of patients with Down syndrome, there is a decline in the expression of this complex, resulting in the transcription of the DYRK1A gene [12].