Publications by authors named "Marcel M A M Mannens"

Autosomal dominant CDK13-related disease is characterized by congenital heart defects, dysmorphic facial features, and intellectual developmental disorder (CHDFIDD). Heterozygous pathogenic variants, particularly missense variants in the kinase domain, have previously been described as disease causing. Using the determination of a methylation pattern and comparison with an established episignature, we reveal the first hypomorphic variant in the kinase domain of CDK13, leading to a never before described autosomal recessive form of CHDFIDD in a boy with characteristic features.

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Neurodevelopmental disorder with or without autism or seizures (NEDAUS) is a neurodevelopmental disorder characterized by global developmental delay, speech delay, seizures, autistic features, and/or behavior abnormalities. It is caused by CUL3 (Cullin-3 ubiquitin ligase) haploinsufficiency. We collected clinical and molecular data from 26 individuals carrying pathogenic variants and variants of uncertain significance (VUS) in the CUL3 gene, including 20 previously unreported cases.

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Mendelian disorders, arising from pathogenic variations within single genetic loci, often manifest as neurodevelopmental disorders (NDDs), affecting a significant portion of the pediatric population worldwide. These disorders are marked by atypical brain development, intellectual disabilities, and various associated phenotypic traits. Genetic testing aids in clinical diagnoses, but inconclusive results can prolong confirmation processes.

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Obesity represents a major public health emergency worldwide, and its etiology is shaped by a complex interplay of environmental and genetic factors. Over the last decade, polygenic risk scores (PRS) have emerged as a promising tool to quantify an individual's genetic risk of obesity. The field of PRS in obesity genetics is rapidly evolving, shedding new lights on obesity mechanisms and holding promise for contributing to personalized prevention and treatment.

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In youth with posttraumatic stress disorder (PTSD) non-response rates after treatment are often high. Epigenetic mechanisms such as DNA methylation (DNAm) have previously been linked to PTSD pathogenesis, additionally DNAm may affect response to (psychological) therapies. Besides investigating the direct link between DNAm and treatment response, it might be helpful to investigate the link between DNAm and previously associated biological mechanisms with treatment outcome.

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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).

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The 16p11.2 deletion syndrome is a clinically heterogeneous disorder, characterized by developmental delay, intellectual disability, hyperphagia, obesity, macrocephaly and psychiatric problems. Cases with 16p11.

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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.

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Purpose: Hao-Fountain syndrome (HAFOUS) is a neurodevelopmental disorder caused by pathogenic variants in USP7. HAFOUS is characterized by developmental delay, intellectual disability, speech delay, behavioral abnormalities, autism spectrum disorder, seizures, hypogonadism, and mild dysmorphic features. We investigated the phenotype of 18 participants with HAFOUS and performed DNA methylation (DNAm) analysis, aiming to generate a diagnostic biomarker.

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In this case report, we describe a rare prenatal finding of a small marker chromosome. This marker chromosome corresponds to an inverted duplication of the 13q region 13q31.1q34 (or 13q31.

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(Jumonji, AT-rich interactive domain 2) haploinsufficiency is associated with a clinically distinct neurodevelopmental syndrome. It is characterized by intellectual disability, developmental delay, autistic features, behavior abnormalities, cognitive impairment, hypotonia, and dysmorphic features. acts as a transcriptional repressor protein that is involved in the regulation of histone methyltransferase complexes.

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Purpose: HNRNPU haploinsufficiency is associated with developmental and epileptic encephalopathy 54. This neurodevelopmental disorder is characterized by developmental delay, intellectual disability, speech impairment, and early-onset epilepsy. We performed genome-wide DNA methylation (DNAm) analysis in a cohort of individuals to develop a diagnostic biomarker and gain functional insights into the molecular pathophysiology of HNRNPU-related disorder.

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Fetal alcohol spectrum disorder (FASD) encompasses neurodevelopmental disabilities and physical birth defects associated with prenatal alcohol exposure. Previously, we attempted to identify epigenetic biomarkers for FASD by investigating the genome-wide DNA methylation (DNAm) profiles of individuals with FASD compared to healthy controls. In this study, we generated additional gene expression profiles in a subset of our previous FASD cohort, encompassing the most severely affected individuals, to examine the functional integrative effects of altered DNAm status on gene expression.

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Article Synopsis
  • Congenital anomalies are a significant global health concern, but data on their prevalence in the Caribbean, specifically the ABC islands (Aruba, Bonaire, and Curaçao), is limited.
  • A study was conducted to assess the prevalence of these anomalies using data from live births and stillbirths between 2008 and 2017, finding a total prevalence rate of 242.97 per 10,000 births, with Bonaire reporting the highest rates.
  • The study revealed that while the overall prevalence in the ABC islands is comparable to that of the French West Indies, it is lower than in the Northern Netherlands; specific anomalies like polydactyly were notably more prevalent in the ABC islands compared to other regions.
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Article Synopsis
  • - Clark-Baraitser syndrome, an autosomal dominant intellectual disability disorder, is linked to harmful variants in the THRAP12 gene, which is part of the important ubiquitin pathway responsible for protein regulation.
  • - Many variants in this gene are still classified as uncertain in their significance, leading researchers to use DNA methylation episignature analysis as a diagnostic tool to clarify genetic findings.
  • - The study successfully identified a distinct DNA methylation pattern associated with pathogenic variants, confirming its potential as a clinical biomarker for the syndrome while also exploring its relationship with other neurodevelopmental disorders.
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Alzheimer's disease (AD), the leading cause of dementia, has an estimated heritability of approximately 70%. The genetic component of AD has been mainly assessed using genome-wide association studies, which do not capture the risk contributed by rare variants. Here, we compared the gene-based burden of rare damaging variants in exome sequencing data from 32,558 individuals-16,036 AD cases and 16,522 controls.

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Purpose: Pathogenic variants in genes involved in the epigenetic machinery are an emerging cause of neurodevelopment disorders (NDDs). Lysine-demethylase 2B (KDM2B) encodes an epigenetic regulator and mouse models suggest an important role during development. We set out to determine whether KDM2B variants are associated with NDD.

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Article Synopsis
  • The study focuses on "episignatures," which are unique DNA methylation patterns used as biomarkers for diagnosing various genetic syndromes, particularly neurodevelopmental disorders.
  • Researchers analyzed DNA methylation changes in 65 genetic syndromes, identifying specific differentially methylated probes (DMPs) and regions (DMRs) associated with these conditions.
  • Findings indicated that DMPs and DMRs were mostly located in gene promoters and pathways related to neurodevelopment, highlighting a connection between gene mutations and altered DNA methylation profiles in these disorders.
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Article Synopsis
  • - This research focuses on a neurodevelopmental syndrome linked to pathogenic variants in the Jumonji gene, which results in developmental delays, cognitive impairment, and various other symptoms, highlighting a lack of understanding of its molecular causes.
  • - The study analyzes DNA methylation profiles from 56 controls and 11 patients, revealing a clear differentiation in methylation patterns between patients with pathogenic variants and healthy individuals.
  • - A new DNA methylation signature has been identified as a potential biomarker for the syndrome, which may aid in diagnosis and improve care by distinguishing affected patients from those with variants of uncertain significance.
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Article Synopsis
  • There are significant global disparities in access to genetic services, prompting the establishment of a joint pediatric-genetics clinic in the Dutch Caribbean in 2011, which aimed to address these challenges.
  • A study of 331 patients who underwent genetic testing from 2011 to 2019 revealed that 33% received a confirmed molecular diagnosis, with the highest diagnostic yield noted in patients experiencing seizures and developmental issues.
  • The findings indicated that genetic diagnoses led to significant changes in clinical management for 52% of patients, illustrating that even with limited resources, effective genetic services can improve patient care and outcomes.
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Overlapping clinical phenotypes and an expanding breadth and complexity of genomic associations are a growing challenge in the diagnosis and clinical management of Mendelian disorders. The functional consequences and clinical impacts of genomic variation may involve unique, disorder-specific, genomic DNA methylation episignatures. In this study, we describe 19 novel episignature disorders and compare the findings alongside 38 previously established episignatures for a total of 57 episignatures associated with 65 genetic syndromes.

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Molecular mechanisms at the intersection of inflammation and cardiovascular diseases (CVD) among Africans are still unknown. We performed an epigenome-wide association study to identify loci associated with serum C-reactive protein (marker of inflammation) among Ghanaians and further assessed whether differentially methylated positions (DMPs) were linked to CVD in previous reports, or to estimated CVD risk in the same population. We used the Illumina Infinium® HumanMethylation450 BeadChip to obtain DNAm profiles of blood samples in 589 Ghanaians from the RODAM study (without acute infections, not taking anti-inflammatory medications, CRP levels < 40 mg/L).

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In this study, we sought to characterize synovial tissue obtained from individuals with arthralgia and disease-specific auto-antibodies and patients with established rheumatoid arthritis (RA), by applying an integrative multi-omics approach where we investigated differences at the level of DNA methylation and gene expression in relation to disease pathogenesis. We performed concurrent whole-genome bisulphite sequencing and RNA-Sequencing on synovial tissue obtained from the knee and ankle from 4 auto-antibody positive arthralgia patients and thirteen RA patients. Through multi-omics factor analysis we observed that the latent factor explaining the variance in gene expression and DNA methylation was associated with Swollen Joint Count 66 (SJC66), with patients with SJC66 of 9 or more displaying separation from the rest.

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Background: Recent findings in neuroimaging and epigenetics offer important insights into brain structures and biological pathways of altered gene expression associated with posttraumatic stress disorder (PTSD). However, it is unknown to what extent epigenetic mechanisms are associated with PTSD and its neurobiology in youth.

Methods: In this study, we combined a methylome-wide association study and structural neuroimaging measures in a Dutch cohort of youths with PTSD (8-18 years of age).

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The Caribbean part of the Kingdom of the Netherlands consists of six islands: Aruba, Bonaire, Curaçao, St. Maarten, St. Eustatius, and Saba.

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