Paving Therapeutic Avenues for FOXG1 Syndrome: Untangling Genotypes and Phenotypes from a Molecular Perspective

Development of the central nervous system (CNS) depends on accurate spatiotemporal control of signaling pathways and transcriptional programs. Forkhead Box G1 (FOXG1) is one of the master regulators that play fundamental roles in forebrain development; from the timing of neurogenesis, to the patterning of the cerebral cortex. Mutations in the FOXG1 gene cause a rare neurodevelopmental disorder called FOXG1 syndrome, also known as congenital form of Rett syndrome. Patients presenting with FOXG1 syndrome manifest a spectrum of phenotypes, ranging from severe cognitive dysfunction and microcephaly to social withdrawal and communication deficits, with varying severities. To develop and improve therapeutic interventions, there has been considerable progress towards unravelling the multi-faceted functions of FOXG1 in the neurodevelopment and pathogenesis of FOXG1 syndrome. Moreover, recent advances in genome editing and stem cell technologies, as well as the increased yield of information from high throughput omics, have opened promising and important new avenues in FOXG1 research. In this review, we provide a summary of the clinical features and emerging molecular mechanisms underlying FOXG1 syndrome, and explore disease-modelling approaches in animals and human-based systems, to highlight the prospects of research and possible clinical interventions.

Paving Therapeutic Avenues for FOXG1 Syndrome: Untangling Genotypes and Phenotypes from a Molecular Perspective

Development of the central nervous system (CNS) depends on accurate spatiotemporal control of signalling pathways and transcription programs. Forkhead Box G1 (FOXG1) is one of the master regulators that plays fundamental roles in forebrain development, from the timing of neurogenesis to the patterning of the cerebral cortex. Mutations in the FOXG1 gene cause a rare neurodevelopmental disorder called FOXG1 syndrome, also known as congenital form of Rett syndrome. Patients presenting with FOXG1 syndrome manifest a spectrum of phenotypes ranging from severe cognitive dysfunction and microcephaly to social withdrawal and communication deficits with varying severities. To develop and improve therapeutic interventions, there has been considerable progress towards unravelling the multi-faceted functions of FOXG1 in neurodevelopment and pathogenesis of FOXG1 syndrome. Moreover, recent advances in genome editing and stem cell technologies, as well as increased yield of information from high throughput omics opened promising and important new avenues in FOXG1 research. In this review, we provide a summary of clinical features and emerging molecular mechanisms underlying FOXG1 syndrome, and explore disease-modelling approaches in animals and human-based systems to highlight prospects of research and possible clinical interventions.

Anxiety, Coping, and Stress: Counseling Parents of Children With a Rare Disease

Rare diseases affect an estimated 300 million individuals worldwide, and ∼30 million Americans. One of these diseases, FOXG1 syndrome, is a severe neurological condition that causes medical complications and developmental delays. The majority of those diagnosed with the genetic condition are children, making parenting a challenging experience. The purpose of this investigation was to explore the relationship between anxiety, coping, and stress among parents of children with FOXG1 syndrome, ( N = 84). The objective was to identify how these constructs relate and contribute to one another to best treat parents who are seeking counseling services. Results indicated significant relationships between these constructs. Study implications, limitations, and areas for future research are discussed.

A Forkhead box G1 (FOXG1) gene mutation in an Indian patient with a congenital variant of Rett syndrome.

A congenital variant of rett syndrome or Forkhead box G1 (FOXG1) syndrome is a rareneurodevelopmental disorder characterized by global developmental delay, microcephaly, autisticfeatures, early-onset dyskinesia, and seizures. Once it was described as one atypical variant of rettsyndrome but now considered as a separate entity. The current study found one girl carrying the denovo c.500-501incG frameshift mutation in the FOXG1 gene by genetic analysis during theevaluation for severe chronic encephalopathy. In literature, only one case was reported from Indiawith FOXG1 mutation. The FOXG1 mutation should be considered in children with a history of globaldevelopmental delay, dyskinesia, and microcephaly with characteristic brain neuroimaging findings.

Linkage analysis identifies an isolated strabismus locus at 14q12 overlapping with FOXG1 syndrome region

Strabismus is a common condition, affecting 1%–4% of individuals. Isolated strabismus has been studied in families with Mendelian inheritance patterns. Despite the identification of multiple loci via linkage analyses, no specific genes have been identified from these studies. The current study is based on a seven-generation family with isolated strabismus inherited in an autosomal dominant manner. A total of 13 individuals from a common ancestor have been included for linkage analysis. Among these, nine are affected and four are unaffected. A single linkage signal has been identified at an 8.5 Mb region of chromosome 14q12 with a multipoint LOD (logarithm of the odds) score of 4.69. Disruption of this locus is known to cause FOXG1 syndrome (or congenital Rett syndrome; OMIM #613454 and *164874), in which 84% of affected individuals present with strabismus. With the incorporation of next-generation sequencing and in-depth bioinformatic analyses, a 4 bp non-coding deletion was prioritised as the top candidate for the observed strabismus phenotype. The deletion is predicted to disrupt regulation of FOXG1, which encodes a transcription factor of the Forkhead family. Suggestive of an autoregulation effect, the disrupted sequence matches the consensus FOXG1 and Forkhead family transcription factor binding site and has been observed in previous ChIP-seq studies to be bound by Foxg1 in early mouse brain development. Future study of this specific deletion may shed light on the regulation of FOXG1 expression and may enhance our understanding of the mechanisms contributing to strabismus and FOXG1 syndrome.