FOXP4 and neurodevelopmental disorder: Notably, in humans, heterozygous disruptions of FOXP1 and FOXP4 have also been linked to neurodevelopmental disorders: an intellectual disability syndrome, frequently accompanied with autistic features and language impairment (MIM #613670) (Hamdan et al, 2010; O'Roak et al, 2011; Srivastava et al, 2014; Lozano et al, 2015; Sollis et al, 2016), and a milder developmental disorder with speech/language delays and congenital abnormalities (Snijders Blok et al, 2021), respectively.