Evolution of neuropsychological and behavioral profile in a cohort of pediatric patients with Becker muscular dystrophy in a longitudinal study

It has long been reported that neuropsychological deficits may be present in dystrophinopathies, specifically non-progressive cognitive impairment and a global deficit in executive functions; this neurocognitive profile has been less explored in patients with Becker than Duchenne muscular dystrophy (BMD/DMD). We conducted a longitudinal study to explore the evolution of neuropsychological and behavioural profile in a cohort of paediatric BMD. Seventeen patients with BMD without intellectual disability were assessed using a full battery of tests, including intellectual, adaptive and executive functioning, language and behavioral features. Tests were performed at baseline and after 12 months. The results showed adequate cognitive and adaptive profile with falls in Working Memory, as well as lower scores in executive functions. An improvement was observed in Processing Speed. Behavioral questionnaires confirmed a negative trend, while in normal ranges. We found a statistically significant difference between T0 and T1 in some items exploring executive functions. No statistically significant difference was observed stratifying patients by mutation site or IQ level. In conclusion, our study suggests that BMD patients have a stable neurocognitive profile, while a deflection in the executive functions may be observed. We recommend a careful monitoring to intercept learning disabilities and promptly start a multimodal rehabilitation.

Corrigendum: PTCHD1 gene mutation/deletion: the cognitive-behavioral phenotyping of four case reports

[This corrects the article DOI: 10.3389/fpsyt.2023.1327802.].

PTCHD1 gene mutation/deletion: the cognitive-behavioral phenotyping of four case reports

Introduction

X-linked PTCHD1 gene has recently been pointed as one of the most interesting candidates for involvement in neurodevelopmental disorders (NDs), such as intellectual disability (ID) and autism spectrum disorder (ASD). PTCHD1 encodes the patched domain-containing protein 1 (PTCHD1), which is mainly expressed in the developing brain and adult brain tissues. To date, major studies have focused on the biological function of the PTCHD1 gene, while the mechanisms underlying neuronal alterations and the cognitive-behavioral phenotype associated with mutations still remain unclear.

Methods

With the aim of incorporating information on the clinical profile of affected individuals and enhancing the characterization of the genotype-phenotype correlation, in this study, we analyze the clinical features of four individuals (two children and two adults) in which array-CGH detected a PTCHD1 deletion or in which panel for screening non-syndromal XLID (X-linked ID) detected a PTCHD1 gene variant. We define the neuropsychological and psychopathological profiles, providing quantitative data from standardized evaluations. The assessment consisted of clinical observations, structured interviews, and parent/self-reported questionnaires.

Results

Our descriptive analysis align with previous findings on the involvement of the PTCHD1 gene in NDs. Specifically, our patients exhibited a clinical phenotype characterized by psychomotor developmental delay- ID of varying severity. Interestingly, while ID during early childhood was associated with autistic-like symptomatology, this interrelation was no longer observed in the adult subjects. Furthermore, our cohort did not display peculiar dysmorphic features, congenital abnormalities or comorbidity with epilepsy.

Discussion

Our analysis shows that the psychopathological and behavioral comorbidities along with cognitive impairment interfere with development, therefore contributing to the severity of disability associated with PTCHD1 gene mutation. Awareness of this profile by professionals and caregivers can promote prompt diagnosis as well as early cognitive and occupational enhancement interventions.

Pathogenic variants in SOX11 mimicking Pitt-Hopkins syndrome phenotype

Pitt-Hopkins syndrome (PTHS) is a rare neurodevelopmental disorder characterised by severe intellectual disability (ID), distinctive facial features and autonomic nervous system dysfunction, caused by TCF4 haploinsufficiency. We clinically diagnosed with PTHS a 14 6/12 -year-old female, who had a normal status of TCF4. The pathogenic c.667del (p.Asp223MetfsTer45) variant in SOX11 was identified through whole exome sequencing (WES). SOX11 variants were initially reported to cause Coffin-Siris syndrome (CSS), characterised by growth restriction, moderate ID, coarse face, hypertrichosis and hypoplastic nails. However, recent studies have provided evidence that they give rise to a distinct neurodevelopmental disorder. To date, SOX11 variants are associated with a variable phenotype, which has been described to resemble CSS in some cases, but never PTHS. By reviewing both clinically and genetically 32 out of 82 subjects reported in the literature with SOX11 variants, for whom detailed information are provided, we found that 7/32 (22%) had a clinical presentation overlapping PTHS. Furthermore, we made a confirmation that overall SOX11 abnormalities feature a distinctive disorder characterised by severe ID, high incidence of microcephaly and low frequency of congenital malformations. Purpose of the present report is to enhance the role of clinical genetics in assessing the individual diagnosis after WES results.

POU3F3-related disorder: Defining the phenotype and expanding the molecular spectrum

POU3F3 variants cause developmental delay, behavioral problems, hypotonia and dysmorphic features. We investigated the phenotypic and genetic landscape, and genotype-phenotype correlations in individuals with POU3F3-related disorders. We recruited unpublished individuals with POU3F3 variants through international collaborations and obtained updated clinical data on previously published individuals. Trio exome sequencing or single exome sequencing followed by segregation analysis were performed in the novel cohort. Functional effects of missense variants were investigated with 3D protein modeling. We included 28 individuals (5 previously published) from 26 families carrying POU3F3 variants; 23 de novo and one inherited from an affected parent. Median age at study inclusion was 7.4 years. All had developmental delay mainly affecting speech, behavioral difficulties, psychiatric comorbidities and dysmorphisms. Additional features included gastrointestinal comorbidities, hearing loss, ophthalmological anomalies, epilepsy, sleep disturbances and joint hypermobility. Autism, hearing and eye comorbidities, dysmorphisms were more common in individuals with truncating variants, whereas epilepsy was only associated with missense variants. In silico structural modeling predicted that all (likely) pathogenic variants destabilize the DNA-binding region of POU3F3. Our study refined the phenotypic and genetic landscape of POU3F3-related disorders, it reports the functional properties of the identified pathogenic variants, and delineates some genotype-phenotype correlations.

Neuropsychological features in RASopathies: A pilot study on parent training program involving families of children with Noonan syndrome

Noonan syndrome (NS) is a clinical variable multisystem disorder caused by mutations in genes encoding proteins involved in the RAS/mitogen-activated protein kinase signaling pathway. NS is characterized by a distinctive facies, short stature, and congenital heart defects. Psychomotor delay, learning difficulties, and social deficits are also common. Furthermore, behavioral and attention problems can be reckoned as a key symptom in NS, with functioning resembling the patterns observed in attention deficit hyperactivity disorder (ADHD). The complex behavioral phenotype has great impact on the quality of life and raises demanding management issues also for patients' families. Parent management training (PMT) is recommended as first-line treatment for ADHD; however, no study has been performed to test the efficacy of PMT in NS, thus far. The aim of this pilot study is the implementation and evaluation of a PMT dedicated to NS families. Parents of seven children with NS were recruited and underwent to a 10-session PMT. Three different questionnaires were administered to both parents: Conners Parent Rating Scales, Parenting Stress Index Short Form (PSI-SF), and Alabama Parenting Questionnaire (APQ). Our findings on this first small cohort of families indicate that positive perception and satisfaction about the child and the interaction with him increased in mothers after the intervention, as measured respectively by PSI-SF difficult child (DC) and PSI-SF parent-child dysfunctional interaction (PCDI), while mothers' level of stress decreased after the PMT, as indicated by PSI-SF total scores. Furthermore, APQ positive parenting, which measures behaviors of positive relationship with the child, increased in mothers after the intervention. Statistical analysis on fathers' questionnaires did not show significant differences after the PMT sessions. This pilot study suggests that PMT is a promising intervention for parents of NS children with behavioral and ADHD symptoms. Changes in mothers' attitudes and distress indicate that behaviorally oriented programs may help parents to manage with NS phenotype.

Obsessive Compulsive “Paper Handling”: A Potential Distinctive Behavior in Children and Adolescents with KBG Syndrome

KBG syndrome (KBGS; OMIM #148050) is a rare disease characterized by short stature, facial dysmorphism, macrodontia of the upper central incisors, skeletal anomalies, and neurodevelopmental disorder/intellectual disability. It is caused by a heterozygous variant or 16q24.3 microdeletions of the ANKRD11 gene (OMIM #611192), which plays a primary role in neuronal development. KBGS traits are variable, and mild expressions of the phenotype may complicate diagnosis. The present work aims at improving the characterization of KBGS in order to facilitate its recognition. A psychopathological evaluation of 17 subjects affected by KBGS found that 10 patients exhibited peculiar behavior related to “paper handling”. These children and adolescents performed repetitive activities with paper, reminiscent of the hoarding and ordering behaviors characteristic of obsessive compulsive disorder. Their activities were time consuming and carried out in solitary, and forced interruption could generate intense emotional reactions. Paper handling may thus be understood as a potential distinct KBGS symptom akin to an obsessive compulsive symptom. Further research is needed to verify this claim.

Differences and Similarities in Adaptive Functioning between Children with Autism Spectrum Disorder and Williams-Beuren Syndrome: A Longitudinal Study

Background: The last decade has seen a growing number of comparative studies on adaptive profiles between individuals with autism spectrum disorder (ASD) and Williams–Beuren syndrome (WBS), showing shared and syndrome-specific adaptive trajectories. Studies have revealed similarities in global adaptive profiles across conditions, while some differences have been found in preschoolers on the specific sub-domains of communication and socialization. However, the majority of studies that have focused on the differences in adaptive functioning across these two conditions used a cross-sectional design. To the best of our knowledge, there are no studies exploring the differences and similarities of adaptive functioning over time. Methods: We compared longitudinal data of adaptive functioning measured by Vineland Adaptive Behavior Scales (VABS) between two samples of children and adolescents with ASD and WBS, matched for chronological age and cognitive/developmental level at the time of the first evaluation. Results and Conclusions: We did not find any difference on the global adaptive level, both at the first evaluation and over time. However, significant differences emerged on the socialization and communication levels at the time of recruitment. Longitudinal data show that only the socialization domain remains different over time, with individuals with WBS having better functioning than those with ASD. The results on shared and distinct patterns of adaptive functioning between disorders are discussed from a developmental perspective, thus contributing to the implementation of age-specific interventions.

Characterization of Cognitive, Language and Adaptive Profiles of Children and Adolescents with Malan Syndrome

Malan Syndrome (MS) is an ultra-rare overgrowth genetic syndrome due to heterozygous variants or deletions in the Nuclear Factor I X (NFIX) gene. It is characterized by an unusual facial phenotype, generalized overgrowth, intellectual disability (ID) and behavioral problems. Even though limitations in cognitive and adaptive functioning have been previously described, systematic studies on MS cohorts are still lacking. Here, we aim to define the cognitive and adaptive behavior profile of MS children and adolescents, providing quantitative data from standardized evaluations. Subjects included in this study were evaluated from October 2020 to January 2022 and the study is based on a retrospective data archive: fifteen MS individuals were recruited and underwent evaluation with Wechsler Intelligence Scales, Leiter International Performance Scales and Griffith Mental Development Scales for cognitive profiles and with Vineland Adaptive Behavior Scales-II Edition (VABS-II) for adaptive functioning. Language skills and visuomotor integration abilities were assessed too. Comparisons and correlations between scales and subtests were performed. All the assessed MS individuals showed both low cognitive and adaptive functioning. One subject presented with mild ID, five had moderate ID and eight showed severe ID. One female toddler received a diagnosis of psychomotor delay. Linguistic skills were impaired in all individuals, with language comprehension relatively more preserved. Results revealed significant differences between VABS-II subdomains and a strong relationship between cognitive and adaptive functioning. All subjects exhibited mild to moderate ID and adaptive behavior lower than normal, with communication skills being the most affected. Regarding the daily living skills domain, personal and community subscale scores were dramatically lower than for the domestic subdomain, highlighting the importance of considering behavior within developmental and environmental contexts. Our cognitive and adaptive MS characterization provides a more accurate quantitative MS profiling, which is expected to help clinicians to better understand the complexity of this rare disorder.

A deep phenotyping experience: up to date in management and diagnosis of Malan syndrome in a single center surveillance report

Background

Malan syndrome (MALNS) is a recently described ultrarare syndrome lacking guidelines for diagnosis, management and monitoring of evolutive complications. Less than 90 patients are reported in the literature and limited clinical information are available to assure a proper health surveillance.

Results

A multidisciplinary team with high expertise in MALNS has been launched at the “Ospedale Pediatrico Bambino Gesù”, Rome, Italy. Sixteen Italian MALNS individuals with molecular confirmed clinical diagnosis of MALNS were enrolled in the program. For all patients, 1-year surveillance in a dedicated outpatient Clinic was attained. The expert panel group enrolled 16 patients and performed a deep phenotyping analysis directed to clinically profiling the disorder and performing critical revision of previously reported individuals. Some evolutive complications were also assessed. Previously unappreciated features (e.g., high risk of bone fractures in childhood, neurological/neurovegetative symptoms, noise sensitivity and Chiari malformation type 1) requiring active surveillance were identified. A second case of neoplasm was recorded. No major cardiovascular anomalies were noticed. An accurate clinical description of 9 new MALNS cases was provided.

Conclusions

Deep phenotyping has provided a more accurate characterization of the main clinical features of MALNS and allows broadening the spectrum of disease. A minimal dataset of clinical evaluations and follow-up timeline has been proposed for proper management of patients affected by this ultrarare disorder.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-022-02384-9.

Genotype-phenotype spectrum and correlations in Xia-Gibbs syndrome: Report of five novel cases and literature review

Background

Xia‐Gibbs syndrome (XGS) is a rare neurodevelopmental disorder caused by pathogenic variants in the AT‐hook DNA‐binding motif‐containing 1 gene (AHDC1), encoding a protein with a crucial role in transcription and epigenetic regulation, axonogenesis, brain function, and neurodevelopment. AHDC1 variants possibly act through a dominant‐negative mechanism and may interfere with DNA repair processes, leading to genome instability and impaired DNA translesion repair. Variants affecting residues closer to the N‐terminal are thought to determine a milder phenotype with better cognitive performances. However, clean‐cut genotype–phenotype correlations are still lacking.

Cases

In this study, we investigated five subjects with XGS in whom exome sequencing led to the identification of five novel de novo pathogenic variants in AHDC1. All variants were extremely rare and predicted to cause a loss of protein function. The phenotype of the reported patients included developmental delay, hypotonia, and distinctive facial dysmorphisms. Additionally, uncommon clinical features were observed, including congenital hypothyroidism and peculiar skeletal abnormalities.

Conclusions

In this study, we report uncommon XGS features associated with five novel truncating variants in AHDC, thus expanding the genotype and phenotypic spectrum of this complex condition. We also compared our cases to previously reported cases, discussing the current status of genotype–phenotype correlations in XGS.

A Comparison of Adaptive Functioning Between Children With Duplication 7 Syndrome and Williams-Beuren Syndrome: A Pilot Investigation

Interstitial deletions of 7q11.23 cause the well-known Williams-Beuren Syndrome (WBS), while duplication of the same region leads to duplication 7 syndrome (Dup7). Children with WBS share a distinct neurobehavioral phenotype including mild to severe intellectual disability, severely impaired visual spatial abilities, relatively preserved verbal expressive skills, anxiety problems, enhanced social motivation (i.e., hypersociable behaviors) and socio-communicative problems. Children with Dup7 syndrome exhibit some "inverted" features when compared to those of individuals with WBS, such as reduced social motivation and impairment of expressive language. Direct comparison of WBS and Dup7 represents a unique opportunity for the neurobehavioral characterization of the 7q11.23 section. However, most of the available data come from qualitative analysis between different studies. To the best of our knowledge, there are no studies directly comparing features of two matched samples of individuals with WBS and Dup7 syndromes. In this pilot study, we compare the adaptive functioning - measured with the Vineland Adaptive Behavior Scales, Second Edition - of two relatively small samples of children with molecularly confirmed diagnosis of WBS and Dup7 matched for IQ and chronological age, with a particular attention to socialization domain and expressive subdomain. Contrary to our assumption, we have not found any significant difference on socialization domain and expressive subdomains. This pilot investigation suggests that, when matched for chronological age and cognitive level, children with WBS and Dup7 share more similarities than expected. The inverted features that emerge in clinical settings on expressive language and social motivation seem not to differently interfere with the daily abilities to communicate and socialize with meaningful others during daily lives. Differences highlighted by previous undirected comparisons could be due to general and non-specific factors such as cognitive level, which is more severely impaired in individuals with WBS than Dup7. Implications for assessment and treatment are discussed.

Assessment of oppositional defiant disorder and oppositional behavior in children and adolescents with Down syndrome

INTRODUCTION

Children and adolescents with intellectual disability (ID) exhibit higher rates of oppositional defiant disorder (ODD) than typically developing (TD) peers. However, studies focusing on the investigation of ODD prevalence in youth with Down syndrome (DS) are still limited.

METHODS

The current study aimed to investigate the prevalence of ODD clinical and subclinical symptoms in a group of 101 youth with DS (63 boys, 38 girls) ranging in age from 6 to 18 years. Moreover, the prevalence of ODD symptoms, as detected by means of three parent-report questionnaires, was compared with that detected by a semi-structured psychopathological interview, namely, the Schedule for Affective Disorders and Schizophrenia for School Aged Children Present and Lifetime (K-SADS) Version Diagnostic and Statistical Manual of Mental Disorders-5 (DSM-5).

RESULTS

We found that 17% of participants met diagnostic criteria for ODD on the K-SADS, whereas 24% exhibited subclinical symptoms. Results also suggest good specificity of Swanson, Nolan, and Pelham-IV Rating Scale (SNAP-IV), Conners' Parent Rating Scales Long Version (CPRS) and Child Behavior Checklist (CBCL) in detecting ODD symptoms. The investigation of the agreement in the prevalence rates of clinical and subclinical symptoms of ODD between K-SADS and the parent-report questionnaires indicated CPRS as the parent-report questionnaire with the best agreement with K-SADS.

DISCUSSION

This study provides support for the use of parent-report questionnaires to assess ODD symptoms in children and adolescents with DS by evaluating their levels of agreement with a semi-structured psychopathological interview. In particular, our results suggest that CPRS could be considered a suitable screening tool for ODD clinical and subclinical symptoms in youth with DS.

Congenital heart defects in molecularly confirmed KBG syndrome patients

Congenital heart defects (CHDs) are known to occur in 9%-25% of patients with KBG syndrome. In this study we analyzed the prevalence and anatomic types of CHDs in 46 personal patients with KBG syndrome, carrying pathogenetic variants in ANKRD11 or 16q24.3 deletion, and reviewed CHDs in patients with molecular diagnosis of KBG syndrome from the literature. CHD was diagnosed in 15/40 (38%) patients with ANKRD11 variant, and in one patient with 16q24.3 deletion. Left ventricular outflow tract obstructions have been diagnosed in 9/15 (60%), subaortic or muscular ventricular septal defect in 5/15 (33%), dextrocardia in 1/15 (8%). The single patient with 16q24.3 deletion and CHD had complete atrioventricular septal defect (AVSD) with aortic coarctation. Review of KBG patients from the literature and present series showed that septal defects have been diagnosed in 44% (27/61) of the cases, left ventricular tract obstructions in 31% (19/61), AVSD in 18% (11/61). Septal defects have been diagnosed in 78% of total patients with 16q24.3 deletion. Valvar anomalies are frequently diagnosed, prevalently involving the left side of the heart. A distinctive association with AVSD is identifiable and could represent a marker to suggest the diagnosis in younger patients. In conclusion, after precise molecular diagnosis and systematic cardiological screening the prevalence of CHD in KBG syndrome seems to be higher than previously reported in clinical articles. In addition to septal defects, left-sided anomalies and AVSD should be considered. Clinical management of KBG syndrome should include accurate and detailed echocardiogram at time of diagnosis.

Cooperative Parent-Mediated Therapy in Children with Fragile X Syndrome and Williams Beuren Syndrome: A Pilot RCT Study of a Transdiagnostic Intervention-Preliminary Data

Children with fragile X syndrome and William Beuren syndrome share several socio-communicative deficits. In both populations, around 30/35% of individuals meets criteria for autism spectrum disorder on gold standard instruments. Notwithstanding, few studies have explored feasibility and validity of therapy for socio-communicative deficits in individuals with these genetic conditions. In this study, we present preliminary data on a pilot RCT aimed to verify the effectiveness of cooperative parent-mediated therapy for socio-communicative deficits in a transdiagnostic perspective in a small sample of 12 participants. Our preliminary data showed that the experimental group had significant improvement in one socio-communicative skill (responsivity) and in clinical global impression, while the control group in an adaptive measure of socialization and word production. Implications of these results are then discussed.

Ketogenic diet as elective treatment in patients with drug-unresponsive hyperinsulinemic hypoglycemia caused by glucokinase mutations

Background

Hyperinsulinemic hypoglycemia (HI) is the most frequent cause of recurrent hypoglycemia in children. Despite diagnostic and therapeutic advances, it remains an important cause of morbidity, leading to neurological complications, such as psychomotor retardation and epilepsy. Patients with diffuse drug-unresponsive HI manifest neurological impairment and neurobehavioral problems, even though surgically treated with a near-total pancreatectomy. Based on the analogies between HI and GLUT1 deficiency, both presenting with neuroglycopenia and lack of alternative cerebral energy sources, we administered a ketogenic diet (KD) in three drug-unresponsive GCK-HI patients with the aim of preserving neurodevelopment and avoiding the need of a near-total pancreatectomy. They presented recurrent symptomatic hypoglycemia, intellectual disability and refractory epilepsy. Patients were treated with classical KD for 79, 27 and 18 months, respectively.

Results

All patients became asymptomatic in a few days and showed an important improvement of the alert state. Epilepsy disappeared and no appearance of novel hypoglycemic lesions was detected with a brain MRI. Cognitive and adaptive abilities rapidly improved and normalized. IQ rose significantly from 81 to 111 (p = 0.04) in patient 1, from 82 vs 95 (p = 0.04) in patient 2, from 60 to 90 (p = 0.04) in patient 3.

Conclusions

We demonstrated the safety and efficacy of KD in the treatment of drug-unresponsive GCK-HI at a short and long-term. The neuroprotective effects of KD determined the recovery from epilepsy and intellectual disabilities and averted the need of a near-total pancreatectomy. All patients and their families reported an improvement of physical and psychosocial well-being, with a substantial improvement of their quality of life. These results might change the course and the quality of life of these patients and their families, having a relevant impact on human lives. Therefore, KD might be considered the elective treatment in unresponsive forms of GCK-HI.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-021-02045-3.

Unique variants in CLCN3, encoding an endosomal anion/proton exchanger, underlie a spectrum of neurodevelopmental disorders

The genetic causes of global developmental delay (GDD) and intellectual disability (ID) are diverse and include variants in numerous ion channels and transporters. Loss-of-function variants in all five endosomal/lysosomal members of the CLC family of Cl^- channels and Cl^-/H⁺ exchangers lead to pathology in mice, humans, or both. We have identified nine variants in CLCN3, the gene encoding CIC-3, in 11 individuals with GDD/ID and neurodevelopmental disorders of varying severity. In addition to a homozygous frameshift variant in two siblings, we identified eight different heterozygous de novo missense variants. All have GDD/ID, mood or behavioral disorders, and dysmorphic features; 9/11 have structural brain abnormalities; and 6/11 have seizures. The homozygous variants are predicted to cause loss of ClC-3 function, resulting in severe neurological disease similar to the phenotype observed in Clcn3^-/- mice. Their MRIs show possible neurodegeneration with thin corpora callosa and decreased white matter volumes. Individuals with heterozygous variants had a range of neurodevelopmental anomalies including agenesis of the corpus callosum, pons hypoplasia, and increased gyral folding. To characterize the altered function of the exchanger, electrophysiological analyses were performed in Xenopus oocytes and mammalian cells. Two variants, p.Ile607Thr and p.Thr570Ile, had increased currents at negative cytoplasmic voltages and loss of inhibition by luminal acidic pH. In contrast, two other variants showed no significant difference in the current properties. Overall, our work establishes a role for CLCN3 in human neurodevelopment and shows that both homozygous loss of ClC-3 and heterozygous variants can lead to GDD/ID and neuroanatomical abnormalities.

Clinical and individual features associated with maternal stress in young adolescents with autism spectrum disorder

Parents of people with autism spectrum disorder experience both negative stressful and positive events. Several clinical and socio-demographic features of children on the autism spectrum have been associated with parenting stress in their families. However, there have been few studies that focus on adolescents and the role of cognitive impairment has rarely been addressed. The main aim of the present research is to explore associations between autism symptoms, cognitive impairment, emotional and behavioral problems, socio-demographic features, and maternal stress in a sample of young adolescents with Autism Spectrum Disorder with and without cognitive impairment. Cognitive impairment and emotional and behavioral problems are associated with maternal stress, while autism symptoms seem to play a minor role. Maternal education and occupation are only associated with maternal stress in the group with cognitive impairment, while maternal age is stress-associated in the group of adolescents without cognitive impairment. Age-related implications for intervention and future research directions are discussed. LAY SUMMARY: Parents of individuals on the autism spectrum are exposed to both negative stressful and enriching experiences during their parenthood. While the influence of several child characteristics and socio-demographic features on parental stress during childhood has been widely explored in past studies, studies on teenagers are limited. The aim of the present research is to explore the influence of several characteristics on maternal stress levels in families with teenagers on the autism spectrum. We found that cognitive impairment and emotional and behavioral problems are associated with maternal stress, while autism symptoms seem to play a minor role. Socio-demographic features are not associated with maternal stress. Broadly speaking, the subjective perception of parental distress in both groups is less related to teenagers' characteristics then the perception of having a difficult interaction with the teenagers. We divided our participants into two groups (one group with cognitive impairment and the other group without). We found that mothers of teenagers with cognitive impairment are generally more stressed compared to the other group. Furthermore, we confirm that emotional and behavioral problems seem to play a major role in maternal stress (especially in the group without cognitive impairment), while autism symptoms seem to play a minor role. Furthermore, we found that maternal education/occupation and maternal age are associated with maternal stress in the group with and the group without cognitive impairment respectively. This research highlights the association between several variables and stress in mothers of adolescents on the spectrum. Results are discussed in the framework of previous findings highlighting the lack of adequate care and support services for families, especially for those of adolescents on the spectrum with cognitive impairment.

Manic and Depressive Symptoms in Children Diagnosed with Noonan Syndrome

Noonan syndrome (NS) is a dominant clinically variable and genetically heterogeneous developmental disorder caused by germ-line mutations encoding components of the Ras–MAPK signaling pathway. A few studies have investigated psychopathological features occurring in individuals with NS, although they were poorly analyzed. The aim of the present work is to investigate the psychopathological features in children and adolescents with NS focusing on depressive and hypo-manic symptoms. Thirty-seven subjects with molecularly confirmed diagnosis were systematically evaluated through a psychopathological assessment. In addition, an evaluation of the cognitive level was performed. Our analyses showed a high recurrence of attention deficit and hyperactivity disorder symptoms, emotional dysregulation, irritability, and anxiety symptomatology. The mean cognitive level was on the average. The present study provides new relevant information on psychopathological features in individuals with NS. The implications for clinicians are discussed including the monitoring of mood disorders in a clinical evolution.

Longitudinal data of neuropsychological profile in a cohort of Duchenne muscular dystrophy boys without cognitive impairment

The aim of the study was to re-assess neuropsychological profile in a group of boys with Duchenne muscular dystrophy without intellectual disability and neuropsychiatric disorder three years apart from a previous evaluation, to establish possible changes over time. We were also interested in defining more in detail correlation between genotype and neuropsychological phenotype. Thirty-three of the previous 40 subjects (mean age at follow up: 10 years and 7 months) agreed to participate in the follow up study and to perform the new assessment. The results confirm a typical neuropsychological profile, with difficulty in the manipulation of stored information, poor abstract reasoning and planning capacity and impulsiveness, supporting the involvement of a cerebellar striatal cortical network for these children. The more detailed description of subgroups of subjects, according to the real expression of Dp140, let to reveal possible genotype-neuropsychological phenotype correlations, and a more general neuropsychological impairment emerged in boys without Dp140 expression.

Comparison of Adaptive Functioning in Children with Williams Beuren Syndrome and Autism Spectrum Disorder: A Cross-Syndrome Study

Williams Beuren syndrome (WBS) and autism spectrum disorder (ASD) have been long considered as "polar opposite" disorders. Although children with WBS appears to be hypersociable, recent researches have revealed difficulties in socio-communicative skills such as shared attention, showing or giving objects, social relationships comprehension, pragmatic use of language, and emotion's recognition. The aim of this cross-syndrome study is to compare clinician-report adaptive profiles of two wide developmental range children by means of Vineland Adaptive Behavior Scales-Interview Edition, Survey Form. Eighty individuals, 40 with WBS and 40 with ASD (31 preschoolers and 49 scholars) with ASD and WBS matched for chronological age and developmental/cognitive level were recruited. Analysis of domains and subdomains have been reported. Results showed no significant difference in global adaptive level between WBS and ASD in both preschooler and scholar children. Communication domain significantly differ in preschoolers (higher in WBS children), but not in scholars. Expressive subdomain significantly differ in both preschoolers and scholars (higher in WBS children). Play and Leisure subdomain significantly differ in scholars (higher in WBS children), but not in preschoolers. Our results support hypothesis on a shared global adaptive impairment in children with WBS and ASD, by extending this findings to scholar-age children. Analysis of domains and subdomains differences highlight the need for interventions targeting social-pragmatic skills since first years of life. Differences in preschoolers and scholars adaptive profiles could be explained through a developmental perspective. LAY SUMMARY: Little is known about differences in adaptive profiles between Williams Beuren syndrome and autism spectrum disorder. Our results show similarities in global adaptive level and difference in communication level. Furthermore, expressive skills seem to be higher in Williams Beuren Syndrome. Autism Res 2021, 14: 748-758. © 2020 International Society for Autism Research and Wiley Periodicals LLC.

7q11.23 Microduplication Syndrome: Clinical and Neurobehavioral Profiling

7q11.23 Microduplication (dup7q11.23) syndrome is a rare autosomal dominant disorder due to a recurring 1.5 to 1.8 Mb duplication of the Williams-Beuren Syndrome critical region. Dup7q11.23 has been associated with several neuro-behavioral characteristics such as low cognitive and adaptive functioning, expressive language impairment, anxiety problems and autistic features. In the present study, we analyze the clinical features of ten individuals in which array-CGH detected dup7q11.23, spanning from 1.4 to 2.1 Mb. The clinical characteristics associated with dup7q11.23 are discussed with respect to its reciprocal deletion. Consistent with previous studies, we confirm that individuals with dup7q11.23 syndrome do not have a homogeneous clinical profile, although some recurring dysmorphic features were found, including macrocephaly, prominent forehead, elongated palpebral fissures, thin lip vermilion and microstomia. Minor congenital malformations include patent ductus arteriosus, cryptorchidism and pes planus. A common finding is hypotonia and joint laxity, resulting in mild motor delay. Neuropsychological and psychodiagnostic assessment confirm that mild cognitive impairment, expressive language deficits and anxiety are recurring neurobehavioral features. New insights into adaptive, psychopathological and neurodevelopmental profiles are discussed.

Further insight into the neurobehavioral pattern of children carrying the 2p16.3 heterozygous deletion involving NRXN1: Report of five new cases

Increasing evidence links heterozygosity for NRXN1 gene deletions to a clinically wide spectrum of neurodevelopmental, psychiatric, and neurological disorders. However, to date, the neurocognitive and social communication features of children carrying this genomic rearrangement have not been assessed in detail. The cognitive and behavioral profiles of five children carrying a heterozygous NRXN1 deletion were investigated through systematic assessment of the cognitive and developmental levels, adaptive profile and presence of behavioral symptoms and autistic features. Furthermore, four transmitting parents were assessed by means of cognitive, psychopathological and parental stress tests. A below-average cognitive level was documented in all children, and defective adaptive levels were observed in four of them. Three of the five children were diagnosed as having autism spectrum disorder in comorbidity with intellectual disability/global developmental delay, with a major impairment in social communication skills. The remaining two children presented with isolated intellectual disability and an unclassifiable neurodevelopmental disorder, respectively. This study provide data contributing to a more accurate characterization of the neurobehavioral phenotype of individuals carrying heterozygous NRXN1 deletions. This analysis indicates that these structural rearrangements are associated with a variable expression of neuropsychiatric symptoms, and cast some doubts about the incomplete penetrance of the disorder.

TUBB Variants Underlying Different Phenotypes Result in Altered Vesicle Trafficking and Microtubule Dynamics

Tubulinopathies are rare neurological disorders caused by alterations in tubulin structure and function, giving rise to a wide range of brain abnormalities involving neuronal proliferation, migration, differentiation and axon guidance. TUBB is one of the ten β-tubulin encoding genes present in the human genome and is broadly expressed in the developing central nervous system and the skin. Mutations in TUBB are responsible for two distinct pathological conditions: the first is characterized by microcephaly and complex structural brain malformations and the second, also known as “circumferential skin creases Kunze type” (CSC-KT), is associated to neurological features, excess skin folding and growth retardation. We used a combination of immunocytochemical and cellular approaches to explore, on patients’ derived fibroblasts, the functional consequences of two TUBB variants: the novel mutation (p.N52S), associated with basal ganglia and cerebellar dysgenesis, and the previously reported variant (p.M73T), linked to microcephaly, corpus callosum agenesis and CSC-KT skin phenotype. Our results demonstrate that these variants impair microtubule (MT) function and dynamics. Most importantly, our studies show an altered epidermal growth factor (EGF) and transferrin (Tf) intracellular vesicle trafficking in both patients’ fibroblasts, suggesting a specific role of TUBB in MT-dependent vesicular transport.

Defining language disorders in children and adolescents with Noonan Syndrome

Background

Noonan Syndrome is a developmental disorder characterized by a distinctive phenotype including facial dysmorphism, webbed neck, short stature, heart defects, and variable cognitive deficits as major features. Over the years, neuropsychological and behavioral studies explored alteration of cognitive functioning and related domains, such as learning, memory, and attention. To our knowledge, however, data concerning the language profile in this disorder is scarce. The aim of the present study was to detect specific language functioning combining nonverbal intelligence quotient and language abilities and to pinpoint strengths and weaknesses in the language domains.

Methods

The language profile of 37 Italian participants with molecularly confirmed diagnosis of Noonan Syndrome was evaluated using specific tools to assess vocabulary and grammar comprehension and production, as well as phonological development.

Results

We observed that 78% of affected individuals exhibited language impairment. Within language domains, the strong area was lexical production and grammar production was the weak area. Almost half the participants manifested a similar trend of specific language impairment. Nonverbal intelligence quotient only correlated with grammar comprehension.

Conclusion

Our study expands present knowledge about the language profile in NS, and provides data that could enable more effective patient management and appropriate intervention.

Heterozygous missense variants of SPTBN2 are a frequent cause of congenital cerebellar ataxia

Heterozygous missense variants in the SPTBN2 gene, encoding the non-erythrocytic beta spectrin 2 subunit (beta-III spectrin), have been identified in autosomal dominant spinocerebellar ataxia type 5 (SCA5), a rare adult-onset neurodegenerative disorder characterized by progressive cerebellar ataxia, whereas homozygous loss of function variants in SPTBN2 have been associated with early onset cerebellar ataxia and global developmental delay (SCAR14). Recently, heterozygous SPTBN2 missense variants have been identified in a few patients with an early-onset ataxic phenotype. We report five patients with non-progressive congenital ataxia and psychomotor delay, 4/5 harboring novel heterozygous missense variants in SPTBN2 and one patient with compound heterozygous SPTBN2 variants. With an overall prevalence of 5% in our cohort of unrelated patients screened by targeted next-generation sequencing (NGS) for congenital or early-onset cerebellar ataxia, this study indicates that both dominant and recessive mutations of SPTBN2 together with CACNA1A and ITPR1, are a frequent cause of early-onset/congenital non-progressive ataxia and that their screening should be implemented in this subgroup of disorders.

Neurobehavioral features in individuals with Kabuki syndrome

Background

Kabuki syndrome (KS) is a disorder characterized by multiple congenital anomalies affecting development and function of multiple systems. Over the years, researchers have attempted to characterize the neurobehavioral phenotype of KS in cohorts of patients enrolled on the basis of clinical assessment. The availability of molecular testing now allows for recruitment of patients with confirmed KS due to KMT2D and KDM6A.

Methods

The aims of the present study were to investigate the neuropsychological and behavioral profiles of individuals with molecularly confirmed diagnosis of KS, and determine the extent of heterogeneity occurring in these profiles between individuals with clinical diagnosis of KS with and without mutations in KMT2D. We also described performance of our cohort in any neuropsychological domain investigated.

Results

We documented a marked variation in the neuropsychological profile of subjects with clinical diagnosis of KS, even though a relatively homogeneous impairment in linguistic domains and motor skills was observed. No significant difference occurred between mutation‐positive and mutation‐negative groups. Phonological disorders and oromotor dysfunctions were also found, and adaptive functioning was characterized by low performance in daily living and in motor domain.

Conclusion

The present study allowed identification of a distinctive neurobehavioral profile in a cohort of individuals affected by KS with or without molecularly confirmed diagnosis. These findings are expected to help clinicians define more accurately targeted protocols for individualized intervention.

Implicit learning deficit in children with Duchenne muscular dystrophy: Evidence for a cerebellar cognitive impairment?

This study aimed at comparing implicit sequence learning in individuals affected by Duchenne Muscular Dystrophy without intellectual disability and age-matched typically developing children. A modified version of the Serial Reaction Time task was administered to 32 Duchenne children and 37 controls of comparable chronological age. The Duchenne group showed a reduced rate of implicit learning even if in the absence of global intellectual disability. This finding provides further evidence of the involvement of specific aspects of cognitive function in Duchenne muscular dystrophy and on its possible neurobiological substrate.

Psychopathological features in Noonan syndrome

INTRODUCTION

Noonan syndrome (NS) is an autosomal dominant disorder characterized by short stature, skeletal and haematological/lymphatic defects, distinctive facies, cryptorchidism, and a wide spectrum of congenital heart defects. Recurrent features also include variable cognitive deficits and behavioural problems. Recent research has been focused on the assessment of prevalence, age of onset and characterization of psychiatric features in this disorder. Herein, we evaluated the prevalence of attention deficit and hyperactivity disorder (ADHD), anxiety and depressive symptoms and syndromes in a cohort of individuals with clinical and molecular diagnosis of NS.

METHODS

The Kiddie Schedule for Affective Disorders and Schizophrenia for School-Age Children Present and Lifetime version (K-SADS PL) has been used for the assessment of psychiatric disorders according to Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). Multidimensional Anxiety Scale for Children (MASC) and the Children's Depression Inventory (CDI) have been assessed for the evaluation of anxiety and depressive symptoms and syndromes, whereas Conners Teacher and Parent Rating Scales-long version (CRS-R) have been used to evaluate ADHD.

RESULTS

The study included 27 individuals (67% males) with an average age of 10.4 years (range 6-18 years) receiving molecular diagnosis of NS or a clinically related condition, evaluated and treated at the Neuropsychiatric Unit of Children's Hospital Bambino Gesù and at the Center for Rare Diseases of Fondazione Policlinico Universitario Agostino Gemelli, in Rome. Twenty individuals showed mutations in PTPN11, five in SOS1 and two in SHOC2. The mean IQ was 94 (Standard Deviation = 17, min = 56, max = 130). Seventy percent of the individuals (n = 19; 95% Confidence Interval = 52-85%) showed ADHD features, with six individuals reaching DSM-IV-TR criteria for ADHD disorder, and thirteen showing subsyndromal traits. Symptoms or syndrome of anxiety were present in 37% of the cohort (n = 10; 95% Confidence Interval = 19-56%), with two individuals showing anxiety disorder and eight cases exhibiting subsyndromal traits.

CONCLUSION

Our results show individuals with NS do present a very high risk to develop psychiatric disorders or symptoms during paediatric age. Based on these findings, preschool assessment of inattentive, hyperactivity/impulsivity and anxiety/depressive symptoms is recommended in order to plan a personalized treatment for psychological/psychiatric issues in affected individuals. Dedicated prospective studies are required to confirm the present data and better characterize the psychopathological profile in NS.

Clinical and Neurobehavioral Features of Three Novel Kabuki Syndrome Patients with Mosaic KMT2D Mutations and a Review of Literature

Kabuki syndrome (KS) is a rare disorder characterized by multiple congenital anomalies and variable intellectual disability caused by mutations in KMT2D/MLL2 and KDM6A/UTX, two interacting chromatin modifier responsible respectively for 56-75% and 5-8% of the cases. To date, three KS patients with mosaic KMT2D deletions in blood lymphocytes have been described. We report on three additional subjects displaying KMT2D gene mosaics including one in which a single nucleotide change results in a new frameshift mutation (p.L1199HfsX7), and two with already-known nonsense mutations (p.R4484X and p.R5021X). Consistent with previously published cases, mosaic KMT2D mutations may result in mild KS facial dysmorphisms and clinical and neurobehavioral features, suggesting that these characteristics could represent the handles for genetic testing of individuals with slight KS-like traits.

Learning by observation and learning by doing in Down and Williams syndromes

New skills may be learned by active experience (experiential learning or learning by doing) or by observation of others' experience (learning by observation). In general, learning by observation reduces the time and the attempts needed to learn complex actions and behaviors. The present research aimed to compare learning by observation and learning by doing in two clinical populations with different etiology of intellectual disability (ID), as individuals with Down syndrome (DS) and individuals with Williams syndrome (WS), with the hypothesis that specific profiles of learning may be found in each syndrome. To this end, we used a mixture of new and existing data to compare the performances of 24 individuals with DS, 24 individuals with WS and 24 typically developing children on computerized tasks of learning by observation or learning by doing. The main result was that the two groups with ID exhibited distinct patterns of learning by observation. Thus, individuals with DS were impaired in reproducing the previously observed visuo-motor sequence, while they were as efficient as TD children in the experiential learning task. On the other hand, individuals with WS benefited from the observational training while they were severely impaired in detecting the visuo-motor sequence in the experiential learning task (when presented first). The present findings reinforce the syndrome-specific hypothesis and the view of ID as a variety of conditions in which some cognitive functions are more disrupted than others because of the differences in genetic profile and brain morphology and functionality. These findings have important implications for clinicians, who should take into account the genetic etiology of ID in developing learning programs for treatment and education.

Cognitive profile in Duchenne muscular dystrophy boys without intellectual disability: The role of executive functions

The aim of our prospective observational study was to assess profiles of cognitive function and a possible impairment of executive functions in a cohort of boys with Duchenne muscular dystrophy without intellectual and behavior disability. Forty Duchenne boys (range of age: 6 years to 11 years and 6 months) were assessed by Wechsler Intelligence scale and battery of tests including tasks assessing working memory and executive functions (inhibition and switching, problem solving and planning). In our cohort some aspects of cognitive function were often impaired. These included multitasking, problem solving, inhibition and working memory necessary to plan and direct goal oriented behavior. Our results support the suggestion that aspects of cognitive function could be impaired even in boys without intellectual disability and support the hypothesis that executive functions may play an important role in specific aspects of cognitive impairment in Duchenne muscular dystrophy.

A comparison between linguistic skills and socio-communicative abilities in Williams syndrome

BACKGROUND

Individuals with Williams syndrome (WS) show a disharmonic linguistic profile with a clear pattern of strengths and weaknesses. Despite their sociable nature, atypical socio-communicative abilities and deficits in communication and relationship with others have been found.

AIM

The aim of the present study was to investigate whether linguistic skills (LS) were in line with the pragmatic and social use of language and the cognitive development of 32 individuals with WS (18 boys and 14 girls) with a mean chronological age of 12.3 (±4.4) years. To examine the relationship between language and mental age (MA) at different ages, the issue was investigated in children and adolescents/young adults with WS.

METHOD

Measures of LS, including lexical and morphosyntactic competences, and adaptive socio-communicative abilities (ASCA), pertaining to the use of language in daily living social context, were compared with the MA of participants. In a second step, participants with WS were split into two subgroups based on age, and the relationship between LS, ASCA and MA was studied.

RESULTS

Although expressive and receptive LS were generally found to be in line with or better than would be expected for MA, specific deficits in receptive ASCA were documented. LS and ASCA appeared to have a different evolution during the different time windows considered.

CONCLUSIONS

Our results underlined the importance of assessing linguistic abilities in the context of adaptive functioning, to guide educational and rehabilitative strategies for individuals with WS.

Identification of novel and hotspot mutations in the channel domain of ITPR1 in two patients with Gillespie syndrome

ITPR1 encodes an intracellular receptor for inositol 1,4,5-trisphosphate (InsP3) which is highly expressed in the cerebellum and is involved in the regulation of Ca2 + homeostasis. Missense mutations in the InsP3-binding domain (IRBIT) of ITPR1 are frequently associated with early onset cerebellar atrophy. Gillespie syndrome is characterized by congenital ataxia, mild to moderate intellectual disability and iris hypoplasia. Dominant or recessive ITPR1 mutations have been recently associated with this form of syndromic ataxia. We performed next generation sequencing in two simplex families with Gillespie syndrome and identified de novo pathological mutations localized in the C-terminal channel domain of ITPR1 in both patients: a recurrent deletion (p.Lys2596del) and a novel missense mutation (p.Asn2576Ile) close to a point of constriction in the Ca^2 + pore. Our study expands the mutational spectrum of ITPR1 and confirms that ITPR1 screening should be implemented in patients with congenital cerebellar ataxia with or without iris hypoplasia.

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De novo ITPR1 mutations were identified in two patients with Gillespie syndrome.

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The Asn2576Ile mutation is located close to a point of constriction in the Ca^2 + pore.

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ITPR1 is frequently involved in congenital ataxias with or without iris hypoplasia.

Visual perception skills: a comparison between patients with Noonan syndrome and 22q11.2 deletion syndrome

Ventral and dorsal streams are visual pathways deputed to transmit information from the photoreceptors of the retina to the lateral geniculate nucleus and then to the primary visual cortex (V1). Several studies investigated whether one pathway is more vulnerable than the other during development, and whether these streams develop at different rates. The results are still discordant. The aim of the present study was to understand the functionality of the dorsal and the ventral streams in two populations affected by different genetic disorders, Noonan syndrome (NS) and 22q11.2 deletion syndrome (22q11.2DS), and explore the possible genotype-phenotype relationships. 'Form coherence' abilities for the ventral stream and 'motion coherence' abilities for the dorsal stream were evaluated in 19 participants with NS and 20 participants with 22q11.2DS. Collected data were compared with 55 age-matched controls. Participants with NS and 22q11.2DS did not differ in the form coherence task, and their performance was significantly lower than that of controls. However, in the motion coherence task, the group with NS and controls did not differ, and both obtained significantly higher scores than the group with 22q11.2DS. Our findings indicate that deficits in the dorsal stream are related to the specific genotype, and that in our syndromic groups the ventral stream is more vulnerable than the dorsal stream.

Mutations in the IRBIT domain of ITPR1 are a frequent cause of autosomal dominant nonprogressive congenital ataxia

Congenital ataxias are nonprogressive neurological disorders characterized by neonatal hypotonia, developmental delay and ataxia, variably associated with intellectual disability and other neurological or extraneurological features. We performed trio-based whole-exome sequencing of 12 families with congenital cerebellar and/or vermis atrophy in parallel with targeted next-generation sequencing of known ataxia genes (CACNA1A, ITPR1, KCNC3, ATP2B3 and GRM1) in 12 additional patients with a similar phenotype. Novel pathological mutations of ITPR1 (inositol 1,4,5-trisphosphate receptor, type 1) were found in seven patients from four families (4/24, ∼16.8%) all localized in the IRBIT (inositol triphosphate receptor binding protein) domain which plays an essential role in the regulation of neuronal plasticity and development. Our study expands the mutational spectrum of ITPR1-related congenital ataxia and indicates that ITPR1 gene screening should be implemented in this subgroup of ataxias.

Rho Kinase Inhibition Is Essential During In Vitro Neurogenesis and Promotes Phenotypic Rescue of Human Induced Pluripotent Stem Cell-Derived Neurons With Oligophrenin-1 Loss of Function

: Rho-GTPases have relevant functions in various aspects of neuronal development, such as differentiation, migration, and synaptogenesis. Loss of function of the oligophrenin-1 gene (OPHN1) causes X-linked intellectual disability with cerebellar hypoplasia and leads to hyperactivation of the rho kinase (ROCK) pathway. ROCK mainly acts through phosphorylation of the myosin phosphatase targeting subunit 1, triggering actin-myosin contractility. We show that during in vitro neurogenesis, ROCK activity decreases from day 10 until terminal differentiation, whereas in OPHN1-deficient human induced pluripotent stem cells (h-iPSCs), the levels of ROCK are elevated throughout differentiation. ROCK inhibition favors neuronal-like appearance of h-iPSCs, in parallel with transcriptional upregulation of nuclear receptor NR4A1, which is known to induce neurite outgrowth. This study analyzed the morphological, biochemical, and functional features of OPHN1-deficient h-iPSCs and their rescue by treatment with the ROCK inhibitor fasudil, shedding light on the relevance of the ROCK pathway during neuronal differentiation and providing a neuronal model for human OPHN1 syndrome and its treatment.

SIGNIFICANCE

The analysis of the levels of rho kinase (ROCK) activity at different stages of in vitro neurogenesis of human induced pluripotent stem cells reveals that ROCK activity decreases progressively in parallel with the appearance of neuronal-like morphology and upregulation of nuclear receptor NR4A1. These results shed light on the role of the ROCK pathway during early stages of human neurogenesis and provide a neuronal stem cell-based model for the treatment of OPHN1 syndrome and other neurological disorders due to ROCK dysfunction.

A Novel Mutation in RPL10 (Ribosomal Protein L10) Causes X-Linked Intellectual Disability, Cerebellar Hypoplasia, and Spondylo-Epiphyseal Dysplasia

RPL10 encodes ribosomal protein L10 (uL16), a highly conserved multifunctional component of the large ribosomal subunit, involved in ribosome biogenesis and function. Using X-exome resequencing, we identified a novel missense mutation (c.191C>T; p.(A64V)) in the N-terminal domain of the protein, in a family with two affected cousins presenting with X-linked intellectual disability, cerebellar hypoplasia, and spondylo-epiphyseal dysplasia (SED). We assessed the impact of the mutation on the translational capacity of the cell using yeast as model system. The mutation generates a functional ribosomal protein, able to complement the translational defects of a conditional lethal mutation of yeast rpl10. However, unlike previously reported mutations, this novel RPL10 missense mutation results in an increase in the actively translating ribosome population. Our results expand the mutational and clinical spectrum of RPL10 identifying a new genetic cause of SED and highlight the emerging role of ribosomal proteins in the pathogenesis of neurodevelopmental disorders.

Early Neurodevelopmental Findings Predict School Age Cognitive Abilities in Duchenne Muscular Dystrophy: A Longitudinal Study

Objective

Neurodevelopmental and cognitive difficulties are known to occur frequently in boys with Duchenne muscular dystrophy but so far none of the published studies have reported both early neurodevelopmental assessments and cognitive tests in the same cohort. The aim of the present longitudinal study was to establish the correlation between early neurodevelopmental assessments performed in preschool boys and the cognitive scales performed at school age or later.

Methods

We performed cognitive tests at school age (mean age 5.7 year ±1.7 SD) (69 months+19 SD) in a cohort of Duchenne boys, previously assessed using the Griffiths scales before the age of 4 years (mean age when the Griffiths scales were performed 30 months ±8.9 SD).

Results

The range of total Developmental quotients on the Griffiths ranged between 56 and 116 (mean 89 ± 15.6 SD). The total Intelligence Quotients on the Wechsler scales ranged between 35 and 119 (mean 87 ± 17.2 SD). There was a significant correlation between the findings on the two scales. P = <0.0001. When we subdivided the cohort according to site of mutations, there was a difference between boys with mutations upstream exon 44 and those with mutations in exon 44–45 affecting Dp140 on both Developmental and Intelligence Quotient (p 0.01 and p 0,003 respectively).

Conclusions

Our results confirm that Duchenne boys tend to slightly underperform on both neurodevelopmental and cognitive assessments. Early neurodevelopmental findings correlated with the cognitive results obtained at school age with a clear concordance between subscales exploring similar domains on the two scales.

Developmental lag of visuospatial attention in Duchenne muscular dystrophy

Children with Duchenne muscular dystrophy (DMD) present a specific deficit of voluntary attention but to date there has been no clear characterization of their attentional skills. The present study investigated the hypothesis that DMD patients present deficits of both voluntary and automatic visuospatial attention systems and that their performance could be equivalent to that of younger healthy males. Twenty males (mean age 10 years) with diagnosis of DMD, 20 age-matched healthy males (10 years 3 months) and 20 healthy younger males (7 years 6 months) were required to perform two visuospatial attention tasks: voluntary and automatic. In the voluntary task, the performance of the DMD group was significantly worse than that of the age-matched group, and equal to that of the younger controls. In the automatic attention task also, the performance of the DMD patients was less efficient than that of the age-matched controls and equal to that of the younger children. This study supports the previous report of voluntary attention deficit in DMD and extends the evidence to include also an automatic attention system deficit. The development level of attention in DMD patients is below that expected for their age and corresponds to a delay of about three years.

Behavioral phenotype in Costello syndrome with atypical mutation: a case report

Costello syndrome (CS) is a rare genetic disorder caused, in the majority of cases, by germline missense HRAS mutations affecting Gly(12) promoting enhanced signaling through the MAPK and PI3K-AKT signaling cascades. In general, the cognitive profile in CS is characterized by intellectual disability ranging from mild to severe impairment. The first published descriptions of behavior in CS children underlined the presence of irritability and shyness at younger ages with sociable personality and good empathic skills after 4-5 years of age, however some recent studies have reported autistic traits. We report on a 7-year-old boy heterozygous for a rare duplication of codon 37 (p.E37dup) in HRAS, manifesting impaired social interaction and non-verbal communication and with circumscribed interests. These additional features improve phenotype delineation in individuals with rare HRAS mutations, facilitating the development of specific behavioral treatments which could lead to improvement in cases of autism spectrum disorder.

Behavioral profile in RASopathies

Here, we describe neurobehavioral features in patients with RASopathies (i.e., Noonan syndrome, LEOPARD syndrome, Costello syndrome, and cardiofaciocutaneous syndrome), developmental disorders caused by mutations in genes coding transducers participating in the RAS-MAPK signaling cascade. Parents of 70 individuals with a RASopathy were asked to fill out the following questionnaires: Child Behavior Checklist (CBCL), Social Communication Questionnaire version lifetime (SCQ-L), and Modified Checklist for Autism in toddlers (M-CHAT). Data analysis indicated high rates of internalizing (37%) and externalizing problems (31%) on CBCL. Scores over the cut-off were documented in 64% of patients with cardiofaciocutaneous syndrome, 44% with Costello syndrome, and 12% with Noonan syndrome on SCQ-L/M-CHAT. Our findings indicate that mutations promoting dysregulation of the RAS-MAPK cascade mark an increased psychopathological risk and highlight that autistic-like behavior could be underdiagnosed in patients with RASopathies.

Early neurodevelopmental assessment in Duchenne muscular dystrophy

The aim of this study was to assess neurodevelopmental profile in young boys affected by Duchenne muscular dystrophy and to establish the correlation between neurodevelopmental findings, and the type and site of mutations. A structured neurodevelopmental assessment (Griffiths Scale of Mental Development) was performed in 81 DMD boys before the age of four years (range: 7-47 months). The mean total DQ was 87 (SD 15.3). Borderline DQ (between 70 and 84) was found in 32% and DQ below 70 in 12.3% of the patients. Children with mutations upstream or in exon 44 had higher DQ than those with mutations downstream exon 44 which are associated with involvement of dystrophin isoforms expressed at high levels in brain. The difference was significant for total and individual subscale DQ with the exception of the locomotor subscale. Items, such as ability to run fast, or getting up from the floor consistently failed in all children, irrespective of the age or of the site of mutation. Our results help to understand the possible different mechanisms underlying the various aspects of neurodevelopmental delay, suggesting that the involvement of brain dystrophin isoforms may cause a delay in the maturation of coordination and dexterity.

Neurobehavioral phenotype observed in KBG syndrome caused by ANKRD11 mutations

KBG syndrome is a rare disease characterized by typical facial dysmorphism, macrodontia of upper central incisors, skeletal abnormalities, and developmental delay. Recently, mutations in ANKRD11 gene have been identified in a subset of patients with KBG syndrome, while a contiguous gene deletion syndrome involving 16q24.3 region (including ANKRD11) was delineated in patients with facial dysmorphism, autism, intellectual disability, and brain abnormalities. Although numerous evidences point to a central causative role of ANKRD11 in the neurologic features of these patients, their neurocognitive and behavior phenotypes are still poorly characterized. Herein, we report the complete neurological and psychiatric features observed in two patients with KBG syndrome due to ANKRD11 mutations. Both patients show intellectual disabilities, severe impairment in communication skills, deficits in several aspects of executive functions and working memory and anxious traits. Their features are compared with those of previously reported patients with KBG syndrome aiding in the delineation of neurocognitive phenotype associated to ANKRD11 mutations.

Attention deficit hyperactivity disorder and cognitive function in Duchenne muscular dystrophy: phenotype-genotype correlation

OBJECTIVES

To assess attention deficit hyperactivity disorder (ADHD) in boys affected by Duchenne muscular dystrophy (DMD) and to explore the relationship with cognitive abilities and genetic findings.

STUDY DESIGN

Boys with DMD (n = 103; 4-17 years of age, mean: 12.6) were assessed using a cognitive test (Wechsler scales). Assessment of ADHD was based on the Diagnostic Statistical Manual, Fourth Edition, Text Revision criteria and on the long version of the Conners Parents and Teachers Rating Scales.

RESULTS

ADHD was found in 33 of the 103 boys with DMD. Attention problems together with hyperactivity (17/33) or in isolation (15/33) were more frequent than hyperactivity alone, which was found in 1 patient. Intellectual disability (ID) was found in 27/103 (24.6%). Sixty-two of the 103 boys had no ID and no ADHD, 9 had ID but no ADHD, 14 had ADHD but no ID, and 18 had both. ADHD occurred more frequently in association with mutations predicted to affect Dp140 expression (exon 45-55) and in those with mutations predicted to affect all dystrophin product, including Dp71 (ie, those that have promoter region and specific first exon between exons 62 and 63 but were also relatively frequent).

CONCLUSIONS

Our results suggest that ADHD is a frequent feature in DMD. The risk of ADHD appears to be higher in patients carrying mutations predicted to affect dystrophin isoforms expressed in the brain and are known to be associated with higher risk of cognitive impairment.