This website provides information on patients with mutations in the FOXP2 gene (FOXP2, OMIM #605317), including clinical data, molecular data, management and research options.

FOXP2 variants may be inherited or occur de novo. The type of genetic alteration affects whether only speech and language problems are present (FOXP2-only-related speech and language disorder) or if more global developmental and behavioural issues are also likely to occur (FOXP2-plus speech and language disorder).

A variant (mutation) directly disrupting FOXP2 leads to FOXP2-only-related disorder. Whereas a FOXP2-plus disorder may arise due to either: a large copy number variant (CNV i.e., contiguous gene deletion), a structural variant (i.e., chromosome translocation or inversion), or maternal uniparental disomy of chromosome 7 (UPD7) involving FOXP2.

FOXP2-related conditions share a core speech disorder phenotype known as childhood apraxia of speech (CAS). Children with CAS have difficulty in acquiring speech, with delayed onset of first words and a protracted period of speech development relative to peers. For children with CAS, once speech is acquired, it is characterised by an inability to automatically and accurately sequence speech sounds into syllables, syllables into words, and words into sentences with correct prosody. The condition changes across the lifespan with features of CAS resolving to some degree over time, but fluent and intelligible speech production remains a core challenge for affected adults.

In FOXP2-only-related disorders, non-verbal (performance) IQ is typically more preserved compared to verbal IQ. Fine motor skills may be impaired (e.g., buttoning clothes, tying shoelaces), yet gross motor skills (walking, running) are normal. Autistic features and dysmorphic findings have been reported in a small number of affected individuals. In FOXP2-plus-related disorders, oral motor deficits, global developmental delay, and autism spectrum disorder are more common. Not all individuals with a mutation in the FOXP2 gene show these features.

This website was created to share and collect information about clinic, management and research projects to gather more knowledge and provide better treatment of patients with mutations in the FOXP2 gene.

Angela Morgan, PhD, Murdoch Children’s Research Institute and University of Melbourne, Melbourne, Australia, angela.morgan@mcri.edu.au

Simon Fisher, PhD, Max Planck Institute for Psycholinguistics, Nijmegen, Netherlands, simon.fisher@mpi.nl