Who does it affect?
FOXG1 syndrome affects most aspects of development, and children with the condition typically have severe intellectual disability. Abnormal or involuntary movements, such as jerking movements of the arms and legs and repeated hand motions, are common, and most affected children do not learn to sit or walk without assistance. Babies and young children with FOXG1 syndrome often have feeding problems, sleep disturbances, seizures, irritability, and excessive crying. The condition is also characterised by limited communication and social interaction, including poor eye contact and a near absence of speech and language skills. Because of these social impairments, FOXG1 syndrome is classified as an autism spectrum disorder.
FOXG1 syndrome was previously described as a congenital variant of Rett syndrome, which is a similar disorder of brain development. Both disorders are characterised by impaired development, intellectual disability, and problems with communication and language. However, Rett syndrome is diagnosed almost exclusively in females, while FOXG1 syndrome affects both males and females. Rett syndrome also involves a period of apparently normal early development that does not occur in FOXG1 syndrome. Because of these differences, physicians and researchers now usually consider FOXG1 syndrome to be distinct from Rett syndrome.
