Here, we identified compound heterozygous mutations c.731 C > T (p.Ser 244 Leu) and c.2413 G > T (p.Glu 805 X) in the WDR62/MCPH2 gene, which encodes the mitotic centrosomal protein WDR62, in two siblings in a Japanese family with microcephaly using whole-exome sequencing.
Children with deletions or intragenic mutations of FOXG1 also have postnatal microcephaly, morphologic abnormalities of the corpus callosum, and choreiform movements.
Heterozygous loss-of-function mutations in the X-linked CASK gene cause progressive microcephaly with pontine and cerebellar hypoplasia (MICPCH) and severe intellectual disability (ID) in females.
The human homologue (MNBH/DYRK1) of the Drosophila minibrain gene maps to human chromosome 21 within the Down syndrome (DS) critical region and is within the region minimally deleted in chromosome 21-linked microcephaly.
Its complete absence is embryonic lethal while Foxg1 heterozygous mice are viable but display microcephaly, altered hippocampal neurogenesis and behavioral and cognitive deficiencies.
Thus, modeling microcephaly with cerebral organoids and mice reveals a WDR62-CEP170-KIF2A pathway promoting cilium disassembly, disruption of which contributes to microcephaly.
Here we utilized CRISPR/Cas9 approaches to generate three strains of WDR62 mutant mice; WDR62V66M/V66M and WDR62R439H/R439H mice recapitulate conserved missense mutations found in humans with microcephaly, with the third strain being a null allele (WDR62stop/stop).
Here we demonstrate the use of whole-exome sequencing to overcome these obstacles by identifying recessive mutations in WD repeat domain 62 (WDR62) as the cause of a wide spectrum of severe cerebral cortical malformations including microcephaly, pachygyria with cortical thickening as well as hypoplasia of the corpus callosum.
Our data support associations between specific genes and reciprocal subphenotypes (CHD8-macrocephaly and DYRK1A-microcephaly) and replicate the importance of a β-catenin-chromatin-remodeling network to ASD etiology.
The DYRK1A gene was studied by direct sequencing and quantitative PCR in a cohort of 105 patients with ID and at least two symptoms from the Angelman syndrome spectrum (microcephaly < -2.5 SD, ataxic gait, seizures and speech delay).
All five affected individuals with CASK mutations had congenital or postnatal microcephaly, disproportionate brainstem and cerebellar hypoplasia, and severe mental retardation.
The regulation of the post-mitotic neural survival activity of TLE1 depends critically on an interaction with FOXG1, a gene shown to be involved in a postnatal microcephaly syndrome.
Human DYRK1A lies in the Down syndrome critical region on chromosome 21, and heterozygous mutations in the gene cause microcephaly and neurological dysfunction.
The extreme degree of microcephaly in this patient may be ascribed to the haploinsufficiency of DYRK1A, since brain size is severely reduced in heterozygotes for the Dyrk1a null mutation in mice.
Mutations and copy number variants affecting DYRK1A gene encoding the dual-specificity tyrosine phosphorylation-regulated kinase 1A are among the most frequent genetic causes of neurodevelopmental disorders including autism spectrum disorder (ASD) associated with microcephaly, febrile seizures and severe speech acquisition delay.
Hypo- or agenesis of the anterior corpus callosum in combination with acquired microcephaly and neurologic impairment can be an important clue for identifying patients with a mutation in FOXG1.
Microcephaly 2 (MCPH2) is one of the most frequent subtypes of MCPH.WD repeat-containing protein 62 gene (WDR62) is the most frequently mutated gene in MCPH2 patients.