In humans, duplication of the chromosomal 11q13 region, which includes FGF3 and FGF4 causes intellectual disability, craniosynostosis and microcephaly (Grillo et al., 2014; Jehee et al., 2007; Martinez Anaya et al., 2023; Ziebart et al., 2013). Here, FGF4 is linked to Intellectual disability.