Publications by authors named "Anna C Jansen"

Malformations of the brain are common and vary in severity, from negligible to potentially fatal. Their causes have not been fully elucidated. Here, we report pathogenic variants in the core protein-folding machinery TRiC/CCT in individuals with brain malformations, intellectual disability, and seizures.

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The rate of discovery and increased understanding of genetic causes for neurodevelopmental disorders has peaked over the past decade. It is well recognised that some genes show marked variability in neuroradiological phenotypes, and inversely, some radiological phenotypes are associated with several different genetic conditions. However, some readily recognisable brain magnetic resonance imaging (MRI) patterns, especially in the context of corresponding associated clinical findings, should prompt consideration of a pathogenic variant in a specific gene or gene pathway.

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Article Synopsis
  • * The condition is characterized by microcephaly, short stature, and hypotonia, and may be one of the most common single-gene causes of neurodevelopmental issues.
  • * Identifying affected individuals can be done through recognizable facial features, which is important for diagnosis in areas with limited access to advanced genetic testing.
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  • Brain malformations are diverse abnormalities in brain development that affect neural structure and connectivity, often impacting brain size.
  • Effective prenatal detection of these malformations relies on a solid grasp of embryology and developmental anatomy at different stages of pregnancy.
  • This review aims to simplify the process of identifying and characterizing these structural brain issues by examining various neuroimaging techniques, such as prenatal neurosonography and MRI, and incorporating insights from post-mortem imaging throughout different developmental stages.
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  • Inherited glycosylphosphatidylinositol deficiency disorders (IGDs) are rare genetic conditions linked to pathogenic changes in GPI-AP genes, affecting multiple body systems and often presenting with severe neurological symptoms.
  • A study analyzed 83 individuals from 75 families with IGDs, revealing that core symptoms include developmental delays (90%), seizures (83%), and motor issues (64%), along with significant brain imaging findings like cerebral atrophy in 75% of cases.
  • The research highlights a wide range of phenotypic diversity, with no single dysmorphic feature being very common, and notes that individuals with certain genetic variants experience seizures earlier, indicating differences in prognosis based on genetic factors.
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Malformations of cortical development (MCDs) represent a heterogeneous spectrum of disorders characterized by atypical development of the cerebral cortex. MCDs are most often diagnosed on the basis of imaging, although subtle lesions, such as focal cortical dysplasia, may only be revealed on neuropathology. Different subtypes have been defined, including lissencephaly, heterotopia, cobblestone malformation, polymicrogyria, and dysgyria.

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We present a comprehensive multi-omic analysis of the EPISTOP prospective clinical trial of early intervention with vigabatrin for pre-symptomatic epilepsy treatment in Tuberous Sclerosis Complex (TSC), in which 93 infants with TSC were followed from birth to age 2 years, seeking biomarkers of epilepsy development. Vigabatrin had profound effects on many metabolites, increasing serum deoxycytidine monophosphate (dCMP) levels 52-fold. Most serum proteins and metabolites, and blood RNA species showed significant change with age.

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  • - The Aristaless-related homeobox gene on the X chromosome is crucial for brain development, with well-documented disorders in males, but less clear effects in females, who are often asymptomatic.
  • - This study examined 10 unpublished female patients with new pathogenic variants and reviewed 63 previously documented cases, revealing a diverse clinical spectrum among females with these variants.
  • - Findings indicated that 42.5% of female carriers are asymptomatic, while 41% exhibit severe symptoms like intellectual disability or developmental conditions, with a higher prevalence of severe phenotypes in those with de novo variants compared to inherited ones.
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ADNP syndrome, also known as the Helsmoortel-Van der Aa syndrome (HVDAS), is a neurodevelopmental disorder characterized by hypotonia, developmental delay, and intellectual disability. Diagnosis is typically made postnatally, and little is known about prenatal presentation of the disorder. We report a child who presented with intrauterine growth restriction, proportionate microcephaly, and an abnormal skull shape on fetal ultrasound.

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Background: Tuberous sclerosis complex (TSC) is associated with a wide range of physical manifestations for which international clinical recommendations for diagnosis and management have been established. TSC is, however, also associated with a wide range of TSC-Associated Neuropsychiatric Disorders (TAND) that are typically under-identified and under-treated yet associated with a profound burden of disease. The contemporary evidence base for the identification and treatment of TAND is much more limited and, to date, consensus recommendations for the diagnosis and management of TAND have also been limited and non-specific.

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Background: Tuberous sclerosis complex-associated neuropsychiatric disorders (TAND) are often present but underidentified and undertreated in individuals with tuberous sclerosis complex (TSC). The clinician-completed TAND-Lifetime Checklist (TAND-L) was developed to address this identification and treatment gap. Stakeholder engagement identified the need for a TAND Checklist that can (1) be completed by caregivers or individuals with TSC and (2) quantify TAND difficulties.

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Background: Tuberous sclerosis complex (TSC) is a rare and complex genetic disorder, associated with tumor growth in various organ systems, epilepsy, and a range of neuropsychiatric manifestations including intellectual disability. With improving patient-centered care and targeted therapies, patient-reported outcome measures (PROMs) are needed to measure the impact of TSC manifestations on daily functioning. The aim of this study was to develop a TSC-specific PROM for adults that captures the impact of TSC on physical functions, mental functions, activity and participation, and the social support individuals with TSC receive, called the TSC-PROM.

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Metachromatic leukodystrophy (MLD) is a neurodegenerative lysosomal storage disorder caused by biallelic pathogenic variants in the gene encoding arylsulfatase A. Disease onset is variable (with late infantile, early and late juvenile, and adult forms) and treatment options depend on age and disease symptoms at onset. In the past, allo-hematopoietic stem cell transplantation (allo-HSCT) has been the best treatment option, following strict selection criteria.

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Article Synopsis
  • The study focuses on improving the early diagnosis of pediatric rheumatic diseases by analyzing gene expression in blood samples and applying machine learning to develop predictive models.
  • RNA sequencing was performed on blood from children with rheumatic diseases, viral infections, and controls, leading to the development of classification models that successfully distinguished between various disease groups.
  • Results indicated that certain classifiers achieved high accuracy in differentiating rheumatic conditions, highlighting the role of innate immune responses, and suggesting blood transcriptomics combined with machine learning could aid in clinical diagnostics.
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Tuberous sclerosis complex (TSC) is a rare multi-system genetic disorder characterized by a high incidence of epilepsy and neuropsychiatric manifestations known as tuberous-sclerosis-associated neuropsychiatric disorders (TANDs), including autism spectrum disorder (ASD) and intellectual disability (ID). MicroRNAs (miRNAs) are small regulatory non-coding RNAs that regulate the expression of more than 60% of all protein-coding genes in humans and have been reported to be dysregulated in several diseases, including TSC. In the current study, RNA sequencing analysis was performed to define the miRNA and isoform (isomiR) expression patterns in serum.

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Background: Malformations of cortical development (MCDs) have been reported in a subset of patients with pathogenic heterozygous variants in or , genes which encode for subunits of the N-methyl-D-aspartate receptor (NMDAR). The aim of this study was to further define the phenotypic spectrum of NMDAR-related MCDs.

Methods: We report the clinical, radiological and molecular features of 7 new patients and review data on 18 previously reported individuals with NMDAR-related MCDs.

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Introduction: Tuberous Sclerosis Complex (TSC) is a multi-system genetic disorder with various TSC-Associated Neuropsychiatric Disorders (TAND) that significantly impact the mental health and wellbeing of individuals with TSC and their caregivers. TAND represents the number one concern to families worldwide, yet is highly under-identified and under-treated. The clinician-administered TAND-Checklist (Lifetime version, TAND-L) has improved identification of TAND in clinical settings.

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Sex chromosome trisomies (SCTs) are characterized by an extra X- or Y-chromosome (XXX, XXY, XYY). The present study aims to investigate early signs of social communication and social emotional development in very young children with SCT. Thirty-four children with SCT (aged 12-24 months) were included in this study, as well as 31 age-matched controls.

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Background: Tuberous sclerosis complex (TSC)-associated neuropsychiatric disorders (TAND) is an umbrella term for the behavioural, psychiatric, intellectual, academic, neuropsychological and psychosocial manifestations of TSC. Although TAND affects 90% of individuals with TSC during their lifetime, these manifestations are relatively under-assessed, under-treated and under-researched. We performed a comprehensive scoping review of all TAND research to date (a) to describe the existing TAND research landscape and (b) to identify knowledge gaps to guide future TAND research.

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RAC1 is a highly conserved Rho GTPase critical for many cellular and developmental processes. De novo missense RAC1 variants cause a highly variable neurodevelopmental disorder. Some of these variants have previously been shown to have a dominant negative effect.

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Free oligosaccharides (fOSs) are soluble oligosaccharide species generated during N-glycosylation of proteins. Although little is known about fOS metabolism, the recent identification of NGLY1 deficiency, a congenital disorder of deglycosylation (CDDG) caused by loss of function of an enzyme involved in fOS metabolism, has elicited increased interest in fOS processing. The catabolism of fOSs has been linked to the activity of a specific cytosolic mannosidase, MAN2C1, which cleaves α1,2-, α1,3-, and α1,6-mannose residues.

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Article Synopsis
  • Tuberous sclerosis complex (TSC) is a genetic disorder that often leads to neuropsychiatric issues like autism and intellectual disability, with links to brain abnormalities and seizures.
  • This study focused on the expression of the contactin-3 gene (CNTN3) in the brain tissue from TSC patients, finding lower levels in those with the disorder compared to healthy controls.
  • The research showed that CNTN3 expression is present during fetal development, peaks around birth, but decreases as individuals reach adulthood, indicating its potential role in neurodevelopmental deficits related to TSC.
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