Publications by authors named "Johanna M Van Hagen"

Weiss-Kruszka Syndrome (WSKA) is caused by pathogenic variants in ZNF462 representing a rare autosomal dominant congenital anomaly syndrome. It is characterized by global developmental delay, hypotonia, feeding difficulties, and craniofacial abnormalities, documented in fewer than 30 patients. ZNF462, located on chromosome 9p31.

View Article and Find Full Text PDF

The shift to a genotype-first approach in genetic diagnostics has revolutionized our understanding of neurodevelopmental disorders, expanding both their molecular and phenotypic spectra. Kleefstra syndrome (KLEFS1) is caused by EHMT1 haploinsufficiency and exhibits broad clinical manifestations. EHMT1 encodes euchromatic histone methyltransferase-1-a pivotal component of the epigenetic machinery.

View Article and Find Full Text PDF

Chung-Jansen syndrome is a neurodevelopmental disorder characterized by intellectual disability, behavioral problems, obesity and dysmorphic features. It is caused by pathogenic variants in the PHIP gene that encodes for the Pleckstrin homology domain-interacting protein, which is part of an epigenetic modifier protein complex. Therefore, we hypothesized that PHIP haploinsufficiency may impact genome-wide DNA methylation (DNAm).

View Article and Find Full Text PDF

Intellectual disability (ID) is a diverse neurodevelopmental condition and almost half of the cases have a genetic etiology. SGIP1 acts as an endocytic protein that influences the signaling of receptors in neuronal systems related to energy homeostasis through its interaction with endophilins. This study focuses on the generation and characterization of induced pluripotent stem cells (iPSC) from two unrelated patients due to a frameshift variant (c.

View Article and Find Full Text PDF

Pitt-Hopkins syndrome (PTHS) is a neurodevelopmental disorder caused by pathogenic variants in TCF4, leading to intellectual disability, specific morphological features, and autonomic nervous system dysfunction. Epigenetic dysregulation has been implicated in PTHS, prompting the investigation of a DNA methylation (DNAm) "episignature" specific to PTHS for diagnostic purposes and variant reclassification and functional insights into the molecular pathophysiology of this disorder. A cohort of 67 individuals with genetically confirmed PTHS and three individuals with intellectual disability and a variant of uncertain significance (VUS) in TCF4 were studied.

View Article and Find Full Text PDF

Purpose: DISP1 encodes a transmembrane protein that regulates the secretion of the morphogen, Sonic hedgehog, a deficiency of which is a major cause of holoprosencephaly (HPE). This disorder covers a spectrum of brain and midline craniofacial malformations. The objective of the present study was to better delineate the clinical phenotypes associated with division transporter dispatched-1 (DISP1) variants.

View Article and Find Full Text PDF

Precise regulation of gene expression is important for correct neurodevelopment. 9q34.3 deletions affecting the EHMT1 gene result in a syndromic neurodevelopmental disorder named Kleefstra syndrome.

View Article and Find Full Text PDF

Objectives: Clefts of the lip, alveolus and/or palate (CLA/P) are the most common craniofacial congenital malformations in humans. These oral clefts can be divided into non-syndromic (isolated) and syndromic forms. Many cleft-related syndromes are clinically variable and genetically heterogeneous, making it challenging to distinguish syndromic from non-syndromic cases.

View Article and Find Full Text PDF
Article Synopsis
  • Dominant variants in the RARB gene cause MCOPS12, a type of microphthalmia that comes with various birth defects and developmental delays, impacting 25 individuals in this study.
  • The research employed transcriptional assays and structural analysis to evaluate how these RARB variants affect its typical function, revealing both gain-of-function and loss-of-function activities.
  • Findings indicate that while RARB disruption leads to a variety of clinical outcomes, some affected individuals may not show key symptoms like eye abnormalities or motor issues, highlighting the complexity of these genetic variations.
View Article and Find Full Text PDF

We describe the therapeutic journey of a 33-year-old patient with early-onset obesity (BMI 56.7 kg/m) and hyperphagia due to a likely pathogenic heterozygous () gene variant. She was unsuccessfully treated with several intensive lifestyle interventions, gastric bypass surgery (-40 kg weight loss, followed by +39.

View Article and Find Full Text PDF

WDR5 is a broadly studied, highly conserved key protein involved in a wide array of biological functions. Among these functions, WDR5 is a part of several protein complexes that affect gene regulation via post-translational modification of histones. We collected data from 11 unrelated individuals with six different rare germline missense variants in ; one identical variant was found in five individuals and another variant in two individuals.

View Article and Find Full Text PDF

We describe the phenotype of 22 male patients (20 probands) carrying a hemizygous missense variant in MED12. The phenotypic spectrum is very broad ranging from nonspecific intellectual disability (ID) to the three well-known syndromes: Opitz-Kaveggia syndrome, Lujan-Fryns syndrome, or Ohdo syndrome. The identified variants were randomly distributed throughout the gene (p = 0.

View Article and Find Full Text PDF

CHD8, a major autism gene, functions in chromatin remodelling and has various roles involving several biological pathways. Therefore, unsurprisingly, previous studies have shown that intellectual developmental disorder with autism and macrocephaly (IDDAM), the syndrome caused by pathogenic variants in CHD8, consists of a broad range of phenotypic abnormalities. We collected and reviewed 106 individuals with IDDAM, including 36 individuals not previously published, thus enabling thorough genotype-phenotype analyses, involving the CHD8 mutation spectrum, characterization of the CHD8 DNA methylation episignature, and the systematic analysis of phenotypes collected in Human Phenotype Ontology (HPO).

View Article and Find Full Text PDF
Article Synopsis
  • BUD1 mutations lead to significant health issues in two patients, including microcephaly and intellectual disabilities.
  • These mutations impair crucial cellular functions during mitosis, resulting in prolonged mitosis, chromosome missegregation, and anomalies in cell division.
  • The study suggests that these mutations contribute to neurodevelopmental disorders and share similarities with other known genetic syndromes related to cell division and cohesion.
View Article and Find Full Text PDF
Article Synopsis
  • TCF7L2 is a gene that plays a crucial role in the Wnt signaling pathway and has been linked to conditions like intellectual disability and autism, though the details are still unclear.
  • This study examines 11 individuals with new mutations in TCF7L2, highlighting that these mutations can be either truncating or missense, with the latter mainly affecting a specific functional region of the protein.
  • Common traits among the affected individuals include childhood developmental delays, with most achieving normal intelligence later, along with potential eye problems, facial differences, orthopedic issues, and additional neuropsychiatric conditions like autism and ADHD.
View Article and Find Full Text PDF

T-type calcium channels (Cav3.1 to Cav3.3) regulate low-threshold calcium spikes, burst firing and rhythmic oscillations of neurons and are involved in sensory processing, sleep, and hormone and neurotransmitter release.

View Article and Find Full Text PDF

Silver-Russell syndrome (SRS) is an imprinting disorder characterized by prenatal and postnatal growth retardation, relative macrocephaly, feeding difficulties and body asymmetry. Recently, upd(20)mat has been identified in few patients with SRS-like features, suggestive of a new imprinting disorder characterized by prenatal and postnatal growth failure. Here, we describe two male patients with upd(20) and feeding difficulties, prenatal and postnatal growth retardation and normal cognitive development.

View Article and Find Full Text PDF

The Jumonji domain containing 1C (JMJD1C) gene encodes the Jumonji domain-containing protein 1C (JMJD1C) and is a member of the jmJC domain-containing protein family involved in histone demethylation that is expressed in the brain. We report seven, unrelated patients with developmental delays or intellectual disability and heterozygous, de novo sequence variants in JMJD1C. All patients had developmental delays, but there were no consistent additional findings.

View Article and Find Full Text PDF
Article Synopsis
  • Epigenetic integrity is essential for cellular processes, and lysine acetyltransferase 8 (KAT8) plays a key role in acetylating histone H4 at lysine 16, which is vital for brain development and disease regulation.
  • A study on cerebrum-specific knockout mice showed that the absence of KAT8 leads to cerebral hypoplasia and improper development of neural stem and progenitor cells, resulting in faulty cell proliferation and increased cell death.
  • The research also identified nine patients with intellectual disabilities and related issues due to variants in the KAT8 gene, linking impaired H4K16 acetylation to their conditions and suggesting valproate as a potential treatment for epilepsy in some cases
View Article and Find Full Text PDF

Objective: To delineate the epileptology, a key part of the phenotypic spectrum, in a large patient cohort.

Methods: Patients were recruited via investigators' practices or social media. We included patients with (likely) pathogenic variants or chromosome 6p21.

View Article and Find Full Text PDF

Objective: Objective evaluation of the efficacy of tongue lip adhesion (TLA) in the management of Robin sequence (RS).

Study Design: Retrospective cohort study.

Setting: Tertiary referral hospital.

View Article and Find Full Text PDF

ADP-ribosylation, the addition of poly-ADP ribose (PAR) onto proteins, is a response signal to cellular challenges, such as excitotoxicity or oxidative stress. This process is catalyzed by a group of enzymes referred to as poly(ADP-ribose) polymerases (PARPs). Because the accumulation of proteins with this modification results in cell death, its negative regulation restores cellular homeostasis: a process mediated by poly-ADP ribose glycohydrolases (PARGs) and ADP-ribosylhydrolase proteins (ARHs).

View Article and Find Full Text PDF