Consensus recommendations on mental health issues in Phelan-McDermid syndrome

Phelan-McDermid syndrome is a rare genetic condition caused by a deletion encompassing the 22q13.3 region or a pathogenic variant of the gene SHANK3. The clinical presentation is variable, but main characteristics include global developmental delay/intellectual disability (ID), marked speech impairment or delay, along with other features like hypotonia and somatic or psychiatric comorbidities. This publication delineates mental health, developmental and behavioural themes across the lifetime of individuals with PMS as informed by parents/caregivers, experts, and other key professionals involved in PMS care. We put forward several recommendations based on the available literature concerning mental health and behaviour in PMS. Additionally, this article aims to improve our awareness of the importance of considering developmental level of the individual with PMS when assessing mental health and behavioural issues. Understanding how the discrepancy between developmental level and chronological age may impact concerning behaviours offers insight into the meaning of those behaviours and informs care for individuals with PMS, enabling clinicians to address unmet (mental health) care needs and improve quality of life.</p

Morning Plasma Melatonin Differences in Autism: Beyond the Impact of Pineal Gland Volume

While low plasma melatonin, a neuro-hormone synthesized in the pineal gland, has been frequently associated with autism, our understanding of the mechanisms behind it have remained unclear. In this exploratory study, we hypothesized that low melatonin levels in ASD could be linked to a decrease of the pineal gland volume (PGV). PGV estimates with magnetic resonance imaging (MRI) with a voxel-based volumetric measurement method and early morning plasma melatonin levels were evaluated for 215 participants, including 78 individuals with ASD, 90 unaffected relatives, and 47 controls. We first found that both early morning melatonin level and PGV were lower in patients compared to controls. We secondly built a linear model and observed that plasma melatonin was correlated to the group of the participant, but also to the PGV. To further understand the relationship between PGV and melatonin, we generated a normative model of the PGV relationship with melatonin level based on control participant data. We found an effect of PGV on normalized melatonin levels in ASD. Melatonin deficit appeared however more related to the group of the subject. Thus, melatonin variations in ASD could be mainly driven by melatonin pathway dysregulation

Consensus recommendations on organization of care for individuals with Phelan-McDermid syndrome

The manifestations of Phelan-McDermid syndrome (PMS) are complex, warranting expert and multidisciplinary care in all life stages. In the present paper we propose consensus recommendations on the organization of care for individuals with PMS. We indicate that care should consider all life domains, which can be done within the framework of the International Classification of Functioning, Disability and Health (ICF). This framework assesses disability and functioning as the outcome of the individual's interactions with other factors. The different roles within care, such as performed by a centre of expertise, by regional health care providers and by a coordinating physician are addressed. A surveillance scheme and emergency card is provided and disciplines participating in a multidisciplinary team for PMS are described. Additionally, recommendations are provided for transition from paediatric to adult care. This care proposition may also be useful for individuals with other rare genetic neurodevelopmental disorders.</p

Phenotypic effects of genetic variants associated with autism

While over 100 genes have been associated with autism, little is known about the prevalence of variants affecting them in individuals without a diagnosis of autism. Nor do we fully appreciate the phenotypic diversity beyond the formal autism diagnosis. Based on data from more than 13,000 individuals with autism and 210,000 undiagnosed individuals, we estimated the odds ratios for autism associated to rare loss-of-function (LoF) variants in 185 genes associated with autism, alongside 2,492 genes displaying intolerance to LoF variants. In contrast to autism-centric approaches, we investigated the correlates of these variants in individuals without a diagnosis of autism. We show that these variants are associated with a small but significant decrease in fluid intelligence, qualification level and income and an increase in metrics related to material deprivation. These effects were larger for autism-associated genes than in other LoF-intolerant genes. Using brain imaging data from 21,040 individuals from the UK Biobank, we could not detect significant differences in the overall brain anatomy between LoF carriers and non-carriers. Our results highlight the importance of studying the effect of the genetic variants beyond categorical diagnosis and the need for more research to understand the association between these variants and sociodemographic factors, to best support individuals carrying these variants

Exploration of the phenotypic heterogeneity of autism spectrum disorders

Les troubles du spectre autistique (TSA) sont définis par des déficits persistants dans la communication sociale et l'interaction sociale ainsi que par l’aspect restreint et répétitif des comportements et des intérêts. Cette entité recouvre des situations cliniques très hétérogènes, tant par le spectre de sévérité des symptômes que par la variété des comorbidités et des signes associés. Si l’étiologie génétique semble prépondérante, les mécanismes impliqués sont complexes et hétérogènes. Une stratégie possible pour décomposer cette hétérogénéité consiste à s’appuyer sur l’étude des relations phénotype-génotype et de façon plus large sur l’étude de sous-groupes phénotypiques comme les particularités sensorielles, les comorbidités ou les particularités neuro-anatomiques, afin de définir des catégories plus homogènes. L’objectif de la thèse a été d’explorer de façon multimodale l’hétérogénéité de ces troubles. La première partie de ma thèse a porté sur l’exploration des relations phénotype-génotype. La première étude a porté sur l’exploration du syndrome de Jacobsen (JS, délétion en 11q24.2-25) caractérisé par une déficience intellectuelle (DI) et un risque plus élevé de TSA. Dans cette région critique 11q24.2-25, nous avons supposé que l’haplo-insuffisance de la Neurotrimine (NTM) (molécule d'adhésion cellulaire neuronale) pourrait augmenter le risque de TSA et pourrait affecter les volumes des structures du cerveau. Si au final, NTM n’a pu être incriminé comme gène de susceptibilité pour les TSA, les explorations ont fourni de nouvelles informations sur l'impact de la délétion 11q24.2-25 sur l'anatomie du cerveau. En effet, en utilisant la segmentation automatique nous avons exploré la macrocéphalie chez un patient porteur d’une grande délétion de novo touchant NTM et présentant un phénotype clinique de JS : nous avons observé, chez ce patient, un volume accru de structures sous-corticales mais une diminution de la matière grise occipitale. La deuxième étude a porté sur les gènes CNTN5 et CNTN6 qui codent des molécules d'adhésion cellulaire neuronale des voies neuronales sensori-motrices. Les investigations cliniques des patients porteurs de variants délétères de CNTN5 et/ou CNTN6 ont montré que ces patients étaient hypersensibles aux sons et que leurs potentiels évoqués auditifs (PEAs) montraient des changements dans les temps de latence. Ces résultats apportent une nouvelle lumière sur les gènes en lien avec les particularités sensorielles dans les TSA. Je présenterai enfin les résultats préliminaires d’une troisième étude, de liaison, chez une famille multiplexe avec TSA et synesthésie. Dans, la deuxième partie de la thèse j’exposerai une étude exploratoire dans laquelle nous avons émis l'hypothèse que les concentrations plasmatiques abaissées de mélatonine observées chez nos patients TSA (vs contrôles et apparentés) pourraient être liées à une diminution du volume de la glande pinéale (VGP). Les VGP ont été mesurés avec une méthode de mesure volumétrique à base de voxel à partir de l’imagerie par résonance magnétique (IRM). Pour mieux comprendre la relation entre le VGP et les taux de mélatonine plasmatique dans notre population, nous avons généré un modèle normatif. Le déficit en mélatonine semblait plus lié au statut du sujet vis à vis du TSA qu’au VGP. Cette étude nous a conduit à faire l’hypothèse que les variations de la mélatonine dans les TSA pourraient être principalement causées par la dérégulation de la voie de la mélatonine. En conclusion, l’ensemble de ces travaux montre l’importance d’une approche multimodale pour la compréhension des TSA pour ouvrir de nouvelles pistes en terme de stratégie thérapeutique.Autism Spectrum Disorder (ASD) are defined by persistent deficits in social communication and social interaction as well as by the restricted and repetitive nature of behaviors and interests. This entity covers very heterogeneous clinical situations, as much by the spectrum of severity of symptoms as by the variety of comorbidities and associated signs. If the genetic etiology seems preponderant, the mechanisms involved are complex and heterogeneous. One possible strategy to break down this heterogeneity is to rely on the study of phenotype-genotype relationships and more broadly on the study of phenotypic subgroups such as sensory peculiarities, co-morbidities or neuro-anatomical peculiarities, in order to to define more homogeneous categories. The aim of the thesis was to explore multi-modally the heterogeneity of these disorders.The first part of my thesis focused on the exploration of phenotype-genotype relationships. The first study focused on the exploration of Jacobsen syndrome (JS, 11q24.2-25 deletion) characterized by intellectual disability (ID) and a higher risk of ASD. In this critical region 11q24.2-25, we hypothesized that haploinsufficiency of neurotrimin (NTM) (neuronal cell adhesion molecule) may increase the risk of ASD and may affect volumes of brain structures. In the end, NTM could not be incriminated as a susceptibility gene for ASD, but the explorations provided new information on the impact of the 11q24.2-25 deletion on brain anatomy. Indeed, using automatic segmentation we explored macrocephaly in a patient with a large NTM deletion with NTM and a clinical phenotype of JS: we observed an increased volume of subcortical structures in this patient. But a decrease in the occipital gray matter. The second study focused on the CNTN5 and CNTN6 genes that encode neuronal cell adhesion molecules of the sensory-motor neural pathways. Clinical investigations of patients with deleterious variants of CNTN5 and / or CNTN6 showed that these patients were hypersensitive to sound and that their auditory evoked potentials (ABRs) showed changes in latency. These results shed new light on genes related to sensory peculiarities in ASDs. I will present the preliminary results of a third linkage study in a multiplexed family with TSA and synesthesia.In the second part of the thesis, I will expose an exploratory study in which we hypothesized that the lowered plasma concentrations of melatonin observed in our ASD patients (vs controls and related) could be related to a decrease in the volume of the pineal gland (PGV). The PGV were measured with a voxel-based volumetric measurement method from magnetic resonance imaging (MRI). To better understand the relationship between VGP and plasma melatonin levels in our population, we generated a normative model. The melatonin deficiency seemed more related to the subject's status with respect to ASD than to VGP. This study led us to hypothesize that melatonin variations in ASD may be mainly caused by deregulation of the melatonin pathway.In conclusion, all of this work shows the importance of a multimodal approach for understanding ASD to open new avenues in terms of therapeutic strategy

Perception auditive des patients souffrant de troubles du spectre autistique

PARIS7-Xavier Bichat (751182101) / SudocSudocFranceF

Postural control and emotion in children with autism spectrum disorders

Autism Spectrum Disorders subjects (ASD) are well known to have deficits in social interaction. We recorded simultaneously eye movements and postural sway during exploration of emotional faces in children with ASD and typically developing children (TD). We analyzed several postural and ocular parameters. The results showed that all postural parameters were significantly greater in children with ASD; ASD made significantly fewer saccades and had shorter fixation time than TD, particularly in the eyes, and especially for unpleasant emotions. These results suggest that poor postural control of ASD and their impaired visual strategies could be due to a lack of interest in social cognition, causing a delay in the development of the cortical areas, and thus could have an effect on their postural control