Impact of pathogenic variants of the Ras-mitogen-activated protein kinase pathway on major white matter tracts in the human brain.

Noonan syndrome and neurofibromatosis type 1 are genetic conditions linked to pathogenic variants in genes of the Ras-mitogen-activated protein kinase signalling pathway. Both conditions hyper-activate signalling of the Ras-mitogen-activated protein kinase pathway and exhibit a high prevalence of neuropsychiatric disorders. Further, animal models of Noonan syndrome and neurofibromatosis type 1 and human imaging studies show white matter abnormalities in both conditions.

Influences of RASopathies on Neuroanatomical Variation in Children.

Background: RASopathies are a group of disorders characterized by pathogenic mutations in the Ras/mitogen-activated protein kinase (Ras/MAPK) signaling pathway. Distinct pathogenic variants in genes encoding proteins in the Ras/MAPK pathway cause Noonan syndrome (NS) and neurofibromatosis type 1 (NF1), which are associated with increased risk for autism spectrum disorder and attention-deficit/hyperactivity disorder.

Methods: This study examined the effect of RASopathies (NS and NF1) on human neuroanatomy, specifically on surface area (SA), cortical thickness (CT), and subcortical volumes.

Novel effects of Ras-MAPK pathogenic variants on the developing human brain and their link to gene expression and inhibition abilities.

The RASopathies are genetic syndromes associated with pathogenic variants causing dysregulation of the Ras/mitogen-activated protein kinase (Ras-MAPK) pathway, essential for brain development, and increased risk for neurodevelopmental disorders. Yet, the effects of most pathogenic variants on the human brain are unknown. We examined: (1) How Ras-MAPK activating variants of PTPN11/SOS1 protein-coding genes affect brain anatomy.

Novel effects of Ras-MAPK pathogenic variants on the developing human brain and their link to gene expression and inhibition abilities.

The RASopathies are genetic syndromes associated with pathogenic variants causing dysregulation of the Ras/mitogen-activated protein kinase (Ras-MAPK) pathway, essential for brain development, and increased risk for neurodevelopmental disorders. Yet, the effects of most pathogenic variants on the human brain are unknown. We examined: 1.

Preferential looking to eyes versus mouth in early infancy: heritability and link to concurrent and later development.

Background: From birth, infants orient preferentially to faces, and when looking at the face, they attend primarily to eyes and mouth. These areas convey different types of information, and earlier research suggests that genetic factors influence the preference for one or the other in young children.

Methods: In a sample of 535 5-month-old infant twins, we assessed eye (relative to mouth) preference in early infancy, i.

Brain structure in autoimmune Addison's disease.

Long-term disturbances in cortisol levels might affect brain structure in individuals with autoimmune Addison's disease (AAD). This study investigated gray and white matter brain structure in a cohort of young adults with AAD. T1- and diffusion-weighted images were acquired for 52 individuals with AAD and 70 healthy controls, aged 19-43 years, using magnetic resonance imaging.

Syndrome-Specific Neuroanatomical Phenotypes in Girls With Turner and Noonan Syndromes.

Background: Turner syndrome (TS) and Noonan syndrome (NS) are distinct genetic conditions with highly similar physical and neurodevelopmental phenotypes. TS is caused by X chromosome absence, whereas NS results from genetic mutations activating the Ras-mitogen-activated protein kinase signaling pathway. Previous neuroimaging studies in individuals with TS and NS have shown neuroanatomical variations relative to typically developing individuals, a standard comparison group when initially examining a clinical group of interest.

Visual disengagement in young infants in relation to age, sex, SES, developmental level and adaptive functioning.

Visual attention plays a key role in infants' interaction with the environment, and shapes their behavioral and brain development. As such, early problems with flexibly switching gaze from one stimulus to another (visual disengagement) have been hypothesized to lead to developmental difficulties (e.g.

Volitional eye movement control and ADHD traits: a twin study.

Background: Top-down volitional command of eye movements may serve as a candidate endophenotype of ADHD, an important function underlying goal-directed action in everyday life. In this twin study, we examined the relation between performance on a response inhibition eye-tracking paradigm and parent-rated ADHD traits in a population-based twin sample. We hypothesized that altered eye movement control is associated with the severity of ADHD traits and that this association is attributable to genetic factors.

Visual Disengagement: Genetic Architecture and Relation to Autistic Traits in the General Population.

Visual disengagement has been hypothesized as an endophenotype for autism. In this study we used twin modelling to assess the role of genetics in basic measures of visual disengagement, and tested their putative association to autistic traits in the general population. We used the Gap Overlap task in a sample of 492 twins.