Publications by authors named "Jacquemont S"

Copy-number variants (CNVs) that increase the risk for neurodevelopmental disorders also affect cognitive ability. However, such CNVs remain challenging to study due to their scarcity, limiting our understanding of gene-dosage-sensitive biological processes linked to cognitive ability. We performed a genome-wide association study (GWAS) in 258,292 individuals, which identified-for the first time-a duplication at 2q12.

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Background: Fragile X syndrome (FXS) and autism spectrum disorder (ASD) are neurodevelopmental conditions that often have a substantial impact on daily functioning and quality of life. FXS is the most common cause of inherited intellectual disability (ID) and the most common monogenetic cause of ASD. Previous literature has shown that electrophysiological activity measured by electroencephalogram (EEG) during resting state is perturbated in FXS and ASD.

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The role of genetic testing in the domain of neurodevelopmental and psychiatric disorders (NPDs) is gradually changing from providing etiological explanation for the presence of NPD phenotypes to also identifying young individuals at high risk of developing NPDs before their clinical manifestation. In clinical practice, the latter implies a shift towards the availability of individual genetic information predicting a certain liability to develop an NPD (e.g.

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Although the first signs of autism are often observed as early as 18-36 months of age, there is a broad uncertainty regarding future development, and clinicians lack predictive tools to identify those who will later be diagnosed with co-occurring intellectual disability (ID). Here, we developed predictive models of ID in autistic children (n=5,633 from three cohorts), integrating different classes of genetic variants alongside developmental milestones. The integrated model yielded an AUC ROC=0.

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Copy-number variants (CNVs) have been implicated in a variety of neuropsychiatric and cognitive phenotypes. We found that deleterious CNVs are less prevalent in non-European ancestry groups than they are in European ancestry groups of both the UK Biobank (UKBB) and a US replication cohort (SPARK). We also identified specific recurrent CNVs that consistently differ in frequency across ancestry groups in both the UKBB and SPARK.

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Rare recurrent copy number variants (CNVs) at chromosomal loci 22q11.2 and 16p11.2 are genetic disorders with lifespan risk for neuropsychiatric disorders.

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Article Synopsis
  • KMT2C and KMT2D are important enzymes that modify genes, with KMT2C haploinsufficiency recently linked to Kleefstra syndrome 2, a neurodevelopmental disorder (NDD) with unknown clinical details.
  • A study involving 98 individuals found that most pathogenic variants in KMT2C span nearly all its exons, making variant interpretation difficult; the study also established a KMT2C DNA methylation signature for better classification of the disorder.
  • Key features of KMT2C-related NDD include developmental delays, intellectual disabilities, and distinct facial characteristics, setting it apart from similar conditions like Kleefstra and Kabuki syndromes, indicating the need for its renaming and
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Introduction: Metformin has been used as a targeted treatment to potentially improve cognition and slow the typical IQ decline that occurs during development among individuals with fragile X syndrome (FXS). In this follow-up study, we are following the trajectory of IQ and adaptive behavior changes over 1 to 3 years in individuals with FXS who are clinically treated with metformin in an open label trial.

Method: Individuals with FXS ages 6 to 25 years (mean 13.

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Our genetic makeup, together with environmental and social influences, shape our brain's development. Yet, the imaging genetics field has struggled to integrate all these modalities to investigate the interplay between genetic blueprint, environment, human health, daily living skills and outcomes. Hence, we interrogated the Adolescent Brain Cognitive Development (ABCD) cohort to outline the effects of rare high-effect genetic variants on brain architecture and corresponding implications on cognitive, behavioral, psychosocial, and socioeconomic traits.

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Introduction: Rare copy number variants (CNVs) and polygenic risk for intelligence (PRS-IQ) both confer susceptibility for autism spectrum disorder (ASD) but have opposing effects on cognitive ability. The field has struggled to disentangle the effects of these two classes of genomic variants on cognitive ability from their effects on ASD susceptibility, in part because previous studies did not include controls with cognitive measures. We aim to investigate the impact of these genomic variants on ASD risk while adjusting for their known effects on cognitive ability.

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The purpose of this paper was to examine the physical, emotional, social and school functioning domains of quality of life of individuals with Fragile X Syndrome, in relation to mental health and sleep patterns to gain a better understanding of how these aspects are affected by the disorder. This study included 119 individuals with Fragile X Syndrome who were given different cognitive examinations by a neuropsychologist or by parent-proxy questionnaires. This study focused on the Pediatric Quality of Life Inventory (PedsQoL), the Anxiety, Depression and Mood Scale (ADAMS), the Children's Sleep Habits Questionnaire (CSHQ), but did include other cognitive tests (Vineland Adaptive Behaviour Scales, Nonverbal IQ, Autism Diagnostic Observation Schedule).

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Background: Clinicians diagnosing autism rely on diagnostic criteria and instruments in combination with an implicit knowledge based on clinical expertise of the specific signs and presentations associated with the condition. This implicit knowledge influences how diagnostic criteria are interpreted, but it cannot be directly observed. Instead, insight into clinicians' understanding of autism can be gained by investigating their diagnostic certainty.

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There is widespread overlap across major psychiatric disorders, and this is the case at different levels of observations, from genetic variants to brain structures and function and to symptoms. However, it remains unknown to what extent these commonalities at different levels of observation map onto each other. Here, we systematically review and compare the degree of similarity between psychiatric disorders at all available levels of observation.

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Asymmetry between the left and right hemisphere is a key feature of brain organization. Hemispheric functional specialization underlies some of the most advanced human-defining cognitive operations, such as articulated language, perspective taking, or rapid detection of facial cues. Yet, genetic investigations into brain asymmetry have mostly relied on common variants, which typically exert small effects on brain-related phenotypes.

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Thalamic dysfunction has been implicated in multiple psychiatric disorders. We sought to study the mechanisms by which abnormalities emerge in the context of the 22q11.2 microdeletion, which confers significant genetic risk for psychiatric disorders.

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Reciprocal Copy Number Variants (CNVs) at the 16p11.2 locus confer high risk for autism spectrum disorder (ASD) and other neurodevelopmental disorders (NDDs). Morphometric MRI studies have revealed large and pervasive volumetric alterations in carriers of a 16p11.

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Rare recurrent copy number variants (CNVs) at chromosomal loci 22q11.2 and 16p11.2 are among the most common rare genetic disorders associated with significant risk for neuropsychiatric disorders across the lifespan.

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Rare copy number variants (CNVs) and polygenic risk for intelligence (PRS-IQ) both confer risk for autism spectrum disorder (ASD) but have opposing effects on cognitive ability. The field has struggled to disentangle the effects of these two classes of genomic variants on cognitive ability from their effects on ASD risk, in part because previous studies did not include controls with cognitive measures. We aim to investigate the impact of these genomic variants on ASD risk while adjusting for their known effects on cognitive ability.

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Article Synopsis
  • - The study explores pre-mRNA splicing, its critical role in neurodevelopment, and how mutations in spliceosome-related genes U2AF2 and PRPF19 contribute to neurodevelopmental disorders (NDDs).
  • - Researchers found multiple pathogenic variants in U2AF2 and PRPF19 across unrelated individuals, with functional analysis showing that specific U2AF2 variants disrupted normal splicing and neuritogenesis in human neurons.
  • - Additionally, investigations in Drosophila models revealed that the loss of function in U2AF2 and PRPF19 caused severe developmental defects and social issues, pointing to a genetic network wherein splicing factors like Rbfox1 play a significant role in brain development and function. *
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Article Synopsis
  • Carriers of specific genetic variants (1q21.1 distal and 15q11.2 BP1-BP2) show both regional and global brain structure differences compared to noncarriers, but analyzing these differences can be complicated.
  • The study used MRI data from various groups (carriers and noncarriers) to assess how regional brain characteristics diverge from overall brain structure differences.
  • Findings revealed that certain brain regions in carriers exhibited distinct patterns of cortical surface area and thickness that deviated from the global average, suggesting more complex effects of these genetic variants on brain development.
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Background: Pathogenic variants in the zinc finger protein coding genes are rare causes of intellectual disability and congenital malformations. Mutations in the gene causing GDACCF syndrome (global developmental delay, absent or hypoplastic corpus callosum, dysmorphic facies; MIM #617260) have been reported in five individuals so far.

Methods: As a result of an international collaboration using GeneMatcher Phenome Central Repository and personal communications, here we describe the clinical and molecular genetic characteristics of 22 previously unreported individuals.

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This study contributes to a greater understanding of the utility of molecular biomarkers to identify clinical phenotypes of fragile X syndrome (FXS). Correlations of baseline clinical trial data (molecular measures- mRNA, mRNA, MMP9 and FMRP protein expression levels, nonverbal IQ, body mass index and weight, language level, NIH Toolbox, adaptive behavior rating, autism, and other mental health correlates) of 59 participants with FXS ages of 6-32 years are reported. mRNA expression levels correlated positively with adaptive functioning levels, expressive language, and specific NIH Toolbox measures.

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Article Synopsis
  • CNVs are genetic variations that increase the risk of neurodevelopmental and psychiatric disorders, including autism and schizophrenia, impacting brain structures differently based on the specific CNV type.
  • A study was conducted using harmonized protocols on 675 CNV carriers and 782 controls, revealing that all CNVs affected subcortical brain structures like the hippocampus and amygdala, with unique subregional changes identifiable through shape analyses.
  • The results indicate that CNVs have varied effects on brain volume and cognition, with some clustering around adult-onset disorders while others align with autism, enhancing our understanding of the relationship between genetics and neuropsychiatric conditions.
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Article Synopsis
  • Over 100 genes are linked to autism, but the prevalence of rare genetic variants in people without an autism diagnosis is not well understood.
  • This study analyzed data from over 13,000 individuals with autism and 210,000 without, finding that rare loss-of-function variants in autism-associated genes negatively impact intelligence, education, and income.
  • Brain imaging data showed no significant anatomical differences related to these variants, suggesting a need for more research on how genetic factors influence individual experiences beyond autism diagnosis.
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