Neuropsychiatric Aspects of Sotos Syndrome: Explorative Review Building Multidisciplinary Bridges in Clinical Practice

Background: Sotos syndrome is a genetic disorder caused by NSD1 gene (nuclear receptor binding SET domain containing protein 1) variants and characterized by overgrowth, macrocephaly, learning disabilities, and co-occurring neuropsychiatric symptoms. Methods: Literature sources published in 2002-2023 were selected and analyzed from PubMed and Google Scholar databases. Results: Neuropsychiatric symptoms are observed among children and adolescents with Sotos syndrome. The majority have intellectual disabilities or borderline intellect. Verbal IQ is higher than performance IQ. Individuals display difficulties in expressing language. Aggression is reported by parents. Children express autistic behavior, ADHD, anxiety based on phobias, and early bedtime-wake times. Conclusions: Sotos syndrome is associated with neuropsychiatric disorders in children. Slow intellectual and language development, aggressive outbursts, anxiety, autism spectrum disorder, and hyperactivity are present in the newest studies. Comprehensive assistance is needed for Sotos syndrome patients in responding to areas of difficulty. There is still a lack of research on the developmental characteristics of these children and the possibilities of improving psychosocial adaptation by providing multidisciplinary long-term medical, educational, and social care.

Sleep disturbances and behavioral symptoms in pediatric Sotos syndrome

Background

Sotos syndrome (SoS) is a rare overgrowth genetic disease caused by intragenic mutations or microdeletions of the NSD1 gene located on chromosome 5q35. SoS population might present cognitive impairment and a spectrum of behavioral characteristics, with a worse profile in patients with microdeletion. Although patients with SoS are known to have impaired sleep habits, very little data are available. The present study aimed to assess the prevalence of sleep disorders (SDs) in a pediatric cohort of patients with SoS and their correlation with neuropsychiatric profiles.

Methods

We included patients with a SoS diagnosis and age < 18 years; all patients underwent a comprehensive neuropsychological assessment, including evaluation of cognition, adaptive functions through the Adaptive Behavior Assessment System-Second Edition (ABAS-II), and behavioral problems using the Achenbach Child Behavior Checklist (CBCL) and Conners' Parent Rating Scale-Revised (CPRS-R:L) questionnaire. To investigate the presence of SD parents, the Sleep Disturbance Scale for Children (SDSC) was completed.

Results

Thirty-eight patients (M 61%, F 39%, mean age 11.1 ± 4.65 years) were included in the study. Although only two had a prior SD diagnosis, 71.1% (N = 27) exhibited pathological scores on SDSC. No statistically significant associations were found between positive SDSC results and genetic microdeletion, intellectual disability (ID), or other medical conditions/treatments. However, a positive correlation emerged between SDSC scores and Conners' Global Index (p = 0.048) and Restless/Impulsive (p = 0.01) scores, CBCL externalizing (p = 0.02), internalizing (p = 0.01), and total scores (p = 0.05). Conversely, a negative linear relationship was observed between the SDSC score and the ABAS GAC and ABAS CAD scores (p = 0.025).

Conclusion

We detected an SD in 71.1% of our sample, with a positive relation between SD and internalizing and externalizing symptom levels, especially hyperactivity and impulsivity. Our study demonstrated a high prevalence of SD in pediatric patients with SoS, highlighting that all patients should be screened for this problem, which has a great impact on the quality of life of patients and their families.

Short report: Autistic symptoms in Sotos syndrome, preliminary results from a case-control study

BACKGROUND

An extremely heterogeneous neuropsychological phenotype has been reported in Sotos Syndrome (SoS), including socio-communicative and behavioral difficulties referred to Autism Spectrum Disorder (ASD). Nonetheless, to date, only few data are available on the topic.

AIM

To investigate ASD symptoms within a sample of children with SoS in comparison to a matched control group of individuals with idiopathic ASD.

METHODS

A convenience sample of SoS (n = 33, age: 9.8 ± 4.1) and ASD (n = 33, age: 9.9 ± 4.1), was included. Autistic symptoms' assessment was performed through the administration of the Autism Diagnostic Observation Schedule-Second Edition- ADOS-2, the Social Responsiveness Scale -SRS and the Social Communication Questionnaire-SCQ.

RESULTS

72.7% of SoS children presented mild to moderate levels of ASD symptoms as measured by the ADOS-2. Oneway ANOVA analysis showed that SoS individuals presenting lower IQ demonstrated higher ASD symptom's level (p = 0.01). No statistically significant differences emerged between the SoS and ASD groups within the SRS total score domain (p = 0.95).

CONCLUSIONS AND IMPLICATIONS

Our results support the evidence for an increased risk for ASD in SoS, suggesting that the ASD symptoms' assessment should be regularly performed in SoS children, with subsequent important implications in terms of therapeutic strategies and later outcome.

Heterogeneity of Autism Characteristics in Genetic Syndromes: Key Considerations for Assessment and Support

Purpose of Review

Elevated prevalence of autism characteristics is reported in genetic syndromes associated with intellectual disability. This review summarises recent evidence on the behavioural heterogeneity of autism in the following syndromes: Fragile X, Cornelia de Lange, Williams, Prader-Willi, Angelman, Down, Smith-Magenis, and tuberous sclerosis complex. Key considerations for assessment and support are discussed.

Recent Findings

The profile and developmental trajectory of autism-related behaviour in these syndromes indicate some degree of syndrome specificity which may interact with broader behavioural phenotypes (e.g. hypersociability), intellectual disability, and mental health (e.g. anxiety). Genetic subtype and co-occurring epilepsy within syndromes contribute to increased significance of autism characteristics. Autism-related strengths and challenges are likely to be overlooked or misunderstood using existing screening/diagnostic tools and criteria, which lack sensitivity and specificity within these populations.

Summary

Autism characteristics are highly heterogeneous across genetic syndromes and often distinguishable from non-syndromic autism. Autism diagnostic assessment practices in this population should be tailored to specific syndromes. Service provisions must begin to prioritise needs-led support.

Parental Stress and Disability in Offspring: A Snapshot during the COVID-19 Pandemic

Parenting a child with a disability, such as neurodevelopmental disorders and genetic syndromes, implies a high level of stress. During the COVID-19 outbreak—as a period implying additional challenges—few studies have specifically investigated caregivers’ distress among neurodevelopmental disabilities. The objective of the study is to investigate whether during the COVID-19 pandemic, the level of parental stress differs between four disability groups including neurodevelopmental disorders (autism spectrum disorder (ASD), attention deficit and hyperactivity disorder (ADHD)) and genetic syndromes (Rett syndrome (RTT), Sotos syndrome (SS)) in comparison to families with typical development offspring (TD). In total, 220 Italian parents of children affected by neurodevelopmental disabilities (74 ASD, 51 ADHD, 34 SS, 21 RTT, 40 TD; age M 9.4 ± SD 4.2) underwent a standardized evaluation for stress related to parenting through the self-report questionnaire, Parental Stress Index-Short Form (PSI-SF). The main findings show greater levels of parental stress—mainly linked to child behavioral characteristics rather than parental sense of competence—in parents of children affected by a disability in comparison to children with typical development. This study highlights the need to support not only individuals with special needs but also their own caregivers: core figures in the management and outcome of children disorders.

The otolaryngologic manifestations of Sotos syndrome 1: A systematic review

OBJECTIVES

Sotos syndrome 1 (SOTOS1; MIM:117550) is rare genetic disorder characterized by excessive physical growth before and after birth, distinctive facial features, a large and elongated head, and intellectual disability (Sotos et al., 1964; Tatton-Brown et al., 1993). This systematic review aims to determine otolaryngologic conditions and complications of SOTOS1 based on existing literature through a review of current and past case reports and studies regarding SOTOS1.

METHODS

A systematic review of all published literature (1964-2020) describing otolaryngologic conditions and/or complications of patients with SOTOS1. Twenty journal articles met inclusion criteria. These articles included 160 patients diagnosed with SOTOS1.

RESULTS

Of the 160 individuals with SOTOS1 included in this review, 22 (14%) were reported to have otologic conditions. 4 (3%) individuals were reported to have conditions involving the thyroid and parathyroid glands. 2 (1%) individuals were reported to have head & neck tumors. 39 (24%) individuals were reported to have congenital malformations or abnormalities of the head & neck. 47 (29%) individuals were reported to have feeding difficulties. 16% of individuals were reported to have other otolaryngologic conditions.

CONCLUSIONS

Our review found multiple otolaryngologic conditions present in patients with SOTOS1, including hearing loss, otitis, hyperthyroidism, hypothyroidism, head & neck tumors, congenital malformations (high arched palate, cleft lip and palate, macroglossia), feeding difficulties, respiratory difficulties, and speech disorders. Additional studies should be conducted to further assess these associations.

Tatton-Brown-Rahman syndrome: cognitive and behavioural phenotypes

The aim of this case series was to assess and characterize cognitive abilities, autistic traits, and adaptive behaviour in Tatton-Brown-Rahman syndrome (TBRS). The sample included 18 individuals with a clinical and genetic diagnosis of TBRS (11 males, seven females; mean age 17y 7mo, SD 9y 5mo, range 7y 2mo-33y 10mo). The British Ability Scales, Third Edition and the Autism Diagnostic Observation Schedule, Second Edition (ADOS-2) were administered to all participants. The Social Responsiveness Scale, Second Edition and the Vineland Adaptive Behaviour Scales, Third Edition were completed by a parent/caregiver. The majority of participants (n=15) had intellectual disability and General Conceptual Ability scores ranged from 39 to 76 (mean 53.17, SD 12.13). Participants displayed a profile of better verbal ability compared with non-verbal reasoning ability and spatial ability. Autistic traits were prevalent and eight participants scored above the cut-off on the ADOS-2, although symptoms were less pronounced in older individuals. Adaptive functioning was impaired but commensurate with intellectual ability. Overall, TBRS is associated with an uneven cognitive profile and a high prevalence of autistic traits. This has implications for identifying appropriate services and support that may be beneficial for individuals with TBRS. WHAT THIS PAPER ADDS: Tatton-Brown-Rahman syndrome is associated with intellectual disability and impaired adaptive functioning. Autistic traits were prevalent within the sample. Lower intellectual ability and adaptive behaviour were associated with greater severity of autistic traits.

Disrupted epigenetics in the Sotos syndrome neurobehavioral phenotype

PURPOSE OF REVIEW

Sotos syndrome is among a growing list of disorders resulting from mutations in epigenetic machinery genes. These Mendelian disorders of the epigenetic machinery (MDEMs) exhibit phenotypic overlap broadly characterized by intellectual disability and atypical growth and behaviors. Manifestations of Sotos syndrome include a distinct facial appearance, overgrowth, intellectual disability, and behavioral issues. Herein we review key aspects of Sotos syndrome, focusing on the neurobehavioral phenotype. Additionally, we highlight recent advances in our understanding of molecular pathogenesis implicating epigenetic mechanisms.

RECENT FINDINGS

Increasing evidence suggests MDEMs account for ∼19% of intellectual disability and ∼45% of overgrowth combined with intellectual disability, with Sotos syndrome constituting most of the latter. Although the genetic cause of Sotos syndrome, disruption of the histone methyltransferase writer NSD1, is well established, recent studies have further delineated the neurobehavioral phenotype and provided insight into disease pathogenesis. Explicitly, NSD1 target genes accounting for a subset of Sotos syndrome features and a specific DNA methylation signature have been identified.

SUMMARY

Sotos syndrome is, therefore, a genetic disorder with epigenetic consequences. Its characteristic neurobehavioral phenotype and those of related MDEMs illustrate the essential role epigenetic mechanisms play in neurologic development. Improvement in our understanding of molecular pathogenesis has important implications for development of diagnostic tests and therapeutic interventions.

Parent-Reported Communication Abilities of Children with Sotos Syndrome: Evidence from the Children's Communication Checklist-2

Sotos syndrome is a congenital overgrowth syndrome associated with intellectual disability. This study investigated communicative abilities of children with Sotos syndrome (n = 31), using the Children’s Communication Checklist, second edition. A cross-syndrome approach was used to establish the specificity of these abilities. Children with Williams syndrome (n = 34) were used as a comparison group. In both groups, the majority of participants had communicative impairment. Children with Sotos syndrome had an uneven pragmatic language profile and greater impairment with social relations, compared with restricted interests. Overall, children with Sotos syndrome had difficulties with both language structure and pragmatic language and a specific profile of relative difficulty with using nonverbal communication, using context-appropriate language and understanding peer relationships.

Rubinstein-Taybi syndrome: New neuroradiological and neuropsychiatric insights from a multidisciplinary approach

Rubinstein-Taybi syndrome is a rare, autosomal dominant, plurimalformative disorder that is clinically characterized by intellectual disability and a wide spectrum of congenital anomalies; facial dysmorphisms are typical, and broad thumbs and great toes are particularly distinctive. Its genetic basis is only partially known, with a detection rate of approximately 65-70%; specifically, microdeletions or mutations in the CREBBP or EP300 genes can be found. Much is known about its clinical features and health-care protocols, but some areas of clinical knowledge are currently unsolved. In particular, few efforts have been made until now to understand the variability in the neuropsychological and neurobehavioral profile and to deepen knowledge of the neuroradiological malformative pattern. Consequently, little is known about the possible genotype-phenotype correlations of these issues. Here, we report clinical and genetic data from a cohort of 23 RSTS Italian patients. The most common features in brain magnetic resonance imaging (MRI) were dysmorphic aspects of the corpus callosum (73.6%) with or without minor dysmorphisms of cerebellar vermis, periventricular posterior white matter hyperintensity, and other less common anomalies. The most interesting feature on the whole spine MRI scans was the tendency for a low-lying conus medullaris without terminal filum thickening. These data will help to improve neuropsychiatric and neuroradiological knowledge and highlight specific genotype-phenotype correlations.

Characteristics of Autism Spectrum Disorder in Sotos Syndrome

Sotos syndrome is a congenital overgrowth disorder with an incidence of approximately 1 in 14,000. This study investigated behavioural characteristics of ASD within a large cohort of individuals with Sotos syndrome (n = 78). As measured by the Social Responsiveness Scale, second edition (SRS-2), 65 participants (83.33 %) met clinical cut-off (T-score ≥60). There was no significant gender difference in symptom severity. There was a significant effect of age, with lower scores observed in early childhood and adulthood, compared to childhood. Furthermore, individuals with Sotos syndrome appear to display a trait profile that is similar to that identified in ASD. Overall, these findings indicate that the majority of individuals with Sotos syndrome display clinically significant behavioural symptomatology associated with ASD.

Epigenetics of Autism Spectrum Disorder

Autism spectrum disorder (ASD), one of the most common childhood neurodevelopmental disorders (NDDs), is diagnosed in 1 of every 68 children. ASD is incredibly heterogeneous both clinically and aetiologically. The etiopathogenesis of ASD is known to be complex, including genetic, environmental and epigenetic factors. Normal epigenetic marks modifiable by both genetics and environmental exposures can result in epigenetic alterations that disrupt the regulation of gene expression, negatively impacting biological pathways important for brain development. In this chapter we aim to summarize some of the important literature that supports a role for epigenetics in the underlying molecular mechanism of ASD. We provide evidence from work in genetics, from environmental exposures and finally from more recent studies aimed at directly determining ASD-specific epigenetic patterns, focusing mainly on DNA methylation (DNAm). Finally, we briefly discuss some of the implications of current research on potential epigenetic targets for therapeutics and novel avenues for future work.

Histone lysine methylation and congenital heart disease: From bench to bedside (Review)

Histone post-translational modifications (PTM) as one of the key epigenetic regulatory mechanisms that plays critical role in various biological processes, including regulating chromatin structure dynamics and gene expression. Histone lysine methyltransferase contributes to the establishment and maintenance of differential histone methylation status, which can recognize histone methylated sites and build an association between these modifications and their downstream processes. Recently, it was found that abnormalities in the histone lysine methylation level or pattern may lead to the occurrence of many types of cardiovascular diseases, such as congenital heart disease (CHD). In order to provide new theoretical basis and targets for the treatment of CHD from the view of developmental biology and genetics, this review discusses and elaborates on the association between histone lysine methylation modifications and CHD.

Identification of a novel de novo nonsense mutation of the NSD1 gene in monozygotic twins discordant for Sotos syndrome

INTRODUCTION

Sotos syndrome is a congenital overgrowth disorder characterized by facial gestalt, excessively rapid growth, acromegalic features and a non-progressive cerebral disorder with intellectual disability.

METHODOLOGY

The identical male twins showed somewhat different clinical, cognitive and behavioural phenotypes. Abnormal clinical manifestations including seizures, scoliosis, enlarged ventricles, and attention-deficit/hyperactivity disorder (ADHD) were found in the proband (first twin), but not in the sibling (second twin). We used diagnostic exome sequencing (DES) to identify a heterozygous de novo mutation of the NSD1 gene in monozygotic twins with Sotos syndrome.

RESULTS

DES revealed a novel nonsense mutation c.2596G>T (p.Glu866*) of the NSD1 gene in the proband, the first of monozygotic twins. Sanger sequencing analysis of the proband and his family members showed that this nonsense mutation was present in the proband and his sibling, but was absent in their parents, indicating that it occurred with de novo origin.

CONCLUSION

This finding expands the phenotypic spectrum associated with variable expression of the Sotos syndrome caused by NSD1 mutation, and it adds further support for postconceptual mutation, epigenetic change and/or an environmental factor involved in the cause of the Sotos syndrome.

Role of Genetics in the Etiology of Autistic Spectrum Disorder: Towards a Hierarchical Diagnostic Strategy

Progress in epidemiological, molecular and clinical genetics with the development of new techniques has improved knowledge on genetic syndromes associated with autism spectrum disorder (ASD). The objective of this article is to show the diversity of genetic disorders associated with ASD (based on an extensive review of single-gene disorders, copy number variants, and other chromosomal disorders), and consequently to propose a hierarchical diagnostic strategy with a stepwise evaluation, helping general practitioners/pediatricians and child psychiatrists to collaborate with geneticists and neuropediatricians, in order to search for genetic disorders associated with ASD. The first step is a clinical investigation involving: (i) a child psychiatric and psychological evaluation confirming autism diagnosis from different observational sources and assessing autism severity; (ii) a neuropediatric evaluation examining neurological symptoms and developmental milestones; and (iii) a genetic evaluation searching for dysmorphic features and malformations. The second step involves laboratory and if necessary neuroimaging and EEG studies oriented by clinical results based on clinical genetic and neuropediatric examinations. The identification of genetic disorders associated with ASD has practical implications for diagnostic strategies, early detection or prevention of co-morbidity, specific treatment and follow up, and genetic counseling.

Multidimensional Influences on Autism Symptom Measures: Implications for Use in Etiological Research

OBJECTIVE

Growing awareness that symptoms of autism spectrum disorder (ASD) transcend multiple diagnostic categories, and major advances in the identification of genetic syndromes associated with ASD, have led to widespread use of ASD symptom measures in etiologic studies of neurodevelopmental disorders. Insufficient consideration of potentially confounding factors such as cognitive ability or behavior problems can have important negative consequences in interpretation of findings, including erroneous estimation of associations between ASD and etiologic factors.

METHOD

Participants were 388 children 2 to 13 years old with diagnoses of ASD or another neurodevelopmental disorder without ASD. Receiver operating characteristics methods were used to assess the influence of IQ and emotional and behavioral problems on the discriminative ability of 3 widely used ASD symptom measures: the Social Responsiveness Scale (SRS), the Autism Diagnostic Interview-Revised (ADI-R), and the Autism Diagnostic Observation Schedule (ADOS).

RESULTS

IQ influenced the discriminative thresholds of the SRS and ADI-R, and emotional and behavioral problems affected the discriminative thresholds of the SRS, ADI-R, and ADOS. This resulted in low specificity of ASD cutoffs on the SRS and ADI-R for children with intellectual disability without ASD (27-42%) and low specificity across all 3 instruments for children without ASD with increased emotional and behavioral problems (36-59%). Adjustment for these characteristics resulted in improved discriminative ability for all of the ASD measures.

CONCLUSION

The findings indicate that scores on ASD symptom measures reflect far more than ASD symptoms. Valid interpretation of scores on these measures requires steps to account for the influences of IQ and emotional and behavioral problems.