Innovations in Phenotyping and Diagnostics Create Opportunities for Improved Treatment and Genetic Counseling for Rare Diseases.

Genetic counseling and treatment options for rare developmental disabilities (DDs) have been revolutionized by the opportunities made possible by using massively parallel sequencing for diagnostic purposes [...].

Genetic Testing for Global Developmental Delay in Early Childhood.

Importance: Global developmental delay (GDD) is characterized by a complex etiology, diverse phenotypes, and high individual heterogeneity, presenting challenges for early clinical etiologic diagnosis. Cognitive impairment is the core symptom, and despite the pivotal role of genetic factors in GDD development, the understanding of them remains limited. Objectives: To assess the utility of genetic detection in patients with GDD and to examine the potential molecular pathogenesis of GDD to identify targets for early intervention. Design, Setting, and Participants: This multicenter, prospective cohort study enrolled patients aged 12 to 60 months with GDD from 6 centers in China from July 4, 2020, to August 31, 2023. Participants underwent trio whole exome sequencing (trio-WES) coupled with copy number variation sequencing (CNV-seq). Bioinformatics analysis was used to unravel pathogenesis and identify therapeutic targets. Main Outcomes and Measures: The main outcomes of this study involved enhancing the rate of positive genetic diagnosis for GDD, broadening the scope of genetic testing indications, and investigating the underlying pathogenesis. The classification of children into levels of cognitive impairment was based on the developmental quotient assessed using the Gesell scale. Results: The study encompassed 434 patients with GDD (262 [60%] male; mean [SD] age, 25.75 [13.24] months) with diverse degrees of cognitive impairment: mild (98 [23%]), moderate (141 [32%]), severe (122 [28%]), and profound (73 [17%]). The combined use of trio-WES and CNV-seq resulted in a 61% positive detection rate. Craniofacial abnormalities (odds ratio [OR], 2.27; 95% CI, 1.45-3.56), moderate or severe cognitive impairment (OR, 1.69; 95% CI, 1.05-2.70), and age between 12 and 24 months (OR, 1.57; 95% CI, 1.05-2.35) were associated with a higher risk of carrying genetic variants. Additionally, bioinformatics analysis suggested that genetic variants may induce alterations in brain development and function, which may give rise to cognitive impairment. Moreover, an association was found between the dopaminergic pathway and cognitive impairment. Conclusions and Relevance: In this cohort study of patients with GDD, combining trio-WES with CNV-seq was a demonstrable, instrumental strategy for advancing the diagnosis of GDD. The close association among genetic variations, brain development, and clinical phenotypes contributed valuable insights into the pathogenesis of GDD. Notably, the dopaminergic pathway emerged as a promising focal point for potential targets in future precision medical interventions for GDD.

Prevalence and determinants of suspected developmental delays among 12-month-old children in northeast of Iran: a large-scale population-based study.

BACKGROUND: Early identification of suspected developmental delays (SDDs) is crucial for planning early interventions. This study aimed to determine the prevalence of SDDs and the associated determinants in children aged 12 months in the northeast of Iran, using the Age and Stage Questionnaire-3 (ASQ-3) as the evaluative tool. METHODS: This study conducted an analytical cross-sectional design to investigate all children who had completed the ASQ-3 screening form at 12 months of age within the time frame of 2016-2023 in the northeast of Iran. The necessary data were extracted from the electronic health record database associated with Mashhad University of Medical Sciences. To examine the factors associated with SDDs within each domain of the ASQ-3, a multiple logistic regression model was employed, and the results were presented using ORs along with 95% CIs. RESULTS: Over 7 years, 236 476 children (96.74%) underwent routine ASQ-3 screening at 12 months. After excluding certain cases, 226 076 children (95.60%) were included. Among them, 51 593 children (22.82%) had a score below -1 SD, indicating SDD prevalence in at least one domain. The social-personal domain had the highest prevalence with 22 980 children (10.16%), while the gross motor domain had the lowest with 5650 children (2.50%). Logistic regression analysis identified strong predictors of SDDs, including hospitalisation at birth (OR=1.85, 95% CI:1.69 to 2.02), prematurity (OR=1.56, 95% CI: 1.37 to 1.79), urbanisation (OR=1.51, 95% CI: 1.45 to 1.57), boys (OR=1.36, 95% CI: 1.31 to 1.40) and lack of exclusive breast feeding until 6 months (OR=1.30, 95% CI: 1.25 to 1.34). CONCLUSION: The prevalence of SDDs highlights the urgency for prompt action, while considering contributing factors. Policymakers can address modifiable risk factors associated with SDDs, including urbanisation risks, support programmes for immigrant families and the importance of exclusive breast feeding until 6 months. Additionally, it is recommended establishing gender-specific local standard cut-off points for the ASQ.

The use of parent-completed questionnaires to investigate developmental outcomes in large populations of children exposed to antiseizure medications in pregnancy.

OBJECTIVE: This study was undertaken to assess the utility of the Ages and Stages Questionnaire-3rd Edition (ASQ-3) and the Vineland Adaptive Behavior Scales-2nd Edition (VABS-II) as neurodevelopmental screening tools for infants exposed to antiseizure medications in utero, and to examine their suitability for use in large-population signal generation initiatives. METHODS: Participants were women with epilepsy who were recruited from 21 hospitals in England and Northern Ireland during pregnancy between 2014 and 2016. Offspring were assessed at 24 months old using the Bayley Scales of Infant Development-3rd Edition (BSID-III), the VABS-II, and the ASQ-3 (n = 223). The sensitivity and specificity of the ASQ-3 and VABS-II to identify developmental delay at 24 months were examined, using the BSID-III to define cases. RESULTS: The ASQ-3 identified 65 children (29.1%) as at risk of developmental delay at 24 months using standard referral criteria. Using a categorical approach and standard referral criteria to identify delay in the ASQ-3 and BSID-III at 24 months, the ASQ-3 showed excellent sensitivity (90.9%) and moderate specificity (74.1%). Utilizing different cut-points resulted in improved properties and may be preferred in certain contexts. The VABS-II exhibited the strongest psychometric properties when borderline impairment (>1 SD below the mean) was compared to BSID-III referral data (sensitivity = 100.0%, specificity = 96.6%). SIGNIFICANCE: Both the ASQ-3 and VABS-II have good psychometric properties in a sample of children exposed to antiseizure medications when the purpose is the identification of at-risk groups. These findings identify the ASQ-3 as a measure that could be used effectively as part of a tiered surveillance system for teratogenic exposure by identifying a subset of individuals for more detailed investigations. Although the VABS-II has excellent psychometric properties, it is more labor-intensive for both the research team and participants and is available in fewer languages than the ASQ-3.

Diagnosis of Arboleda-Tham syndrome by whole-exome sequencing in an Asian girl with severe developmental delay.

OBJECTIVE: This study aims to report a severe phenotype of Arboleda-Tham syndrome in a 20-month-old girl, characterized by global developmental delay, distinct facial features, intellectual disability. Arboleda-Tham syndrome is known for its wide phenotypic spectrum and is associated with truncating variants in the KAT6A gene. METHODS: To diagnose this case, a combination of clinical phenotype assessment and whole-exome sequencing technology was employed. The genetic analysis involved whole-exome sequencing, followed by confirmation of the identified variant through Sanger sequencing. RESULTS: The whole-exome sequencing revealed a novel de novo frameshift mutation c.3048del (p.Leu1017Serfs*17) in the KAT6A gene, which is classified as likely pathogenic. This mutation was not found in the ClinVar and HGMD databases and was not present in her parents. The mutation leads to protein truncation or activation of nonsense-mediated mRNA degradation. The mutation is located within exon 16, potentially leading to protein truncation or activation of nonsense-mediated mRNA degradation. Protein modeling suggested that the de novo KAT6A mutation might alter hydrogen bonding and reduce protein stability, potentially damaging the protein structure and function. CONCLUSION: This study expands the understanding of the genetic basis of Arboleda-Tham syndrome, highlighting the importance of whole-exome sequencing in diagnosing cases with varied clinical presentations. The discovery of the novel KAT6A mutation adds to the spectrum of known pathogenic variants and underscores the significance of this gene in the syndrome's pathology.

"Everyone screens to some extent": Barriers and facilitators of developmental screening among children with sickle cell disease: A mixed methods study.

BACKGROUND: Developmental delays are common among children with sickle cell disease (SCD). Existing guidelines support consistent screening to increase the identification of deficits and support referral to rehabilitative interventions, yet adherence remains variable. This study sought to assess current practices and identify barriers and facilitators to improve developmental screening for children 0-3 years with SCD. PROCEDURE: A mixed methods approach, guided by the Exploration and Preparation stages of the Exploration, Preparation, Implementation, and Sustainment (EPIS) framework, assessed developmental screening practices among primary care providers and hematologists. Phase 1 included the SCD Developmental Surveillance and Screening Guideline and Practice Survey. Phase 2 included the SCD Developmental Screening Organizational Survey alongside semi-structured interviews. Descriptive and qualitative methods summarized the findings. RESULTS: Thirty-three providers from general pediatrics and hematology completed phase 1. Use of standardized developmental screening measures was variable, with the most frequently used being the Modified Checklist for Autism in Toddlers (77%) and the Ages and Stages Questionnaire (55%). Fifteen providers participated in phase 2, and reported they were most likely to engage in changes to improve their practice (mean = 4.4/5) and least likely to support spiritual health and well-being (mean = 3.5/5). Three themes emerged:(i) developmental screening is not standardized or specific to SCD, (ii) children with SCD benefit from a multidisciplinary team, and (iii) healthcare system limitations are a barrier. CONCLUSIONS: Developmental screening is inconsistent and insufficient for young children with SCD. Providers are interested in supporting children with SCD, but report a lack of standardized measures and consistent guidance as barriers.

Late-Onset Molybdenum Cofactor Deficiency Type A: A Treatable Cause of Developmental Delay.

Molybdenum cofactor deficiency classically presents in neonates with intractable seizures; however, milder cases generally present before age 2 years with developmental delays and may go undiagnosed. Early diagnosis, and safe, US Food and Drug Administration-approved substrate replacement are critical to preserve neurologic function. This article discusses 2 children who presented with late-onset molybdenum cofactor deficiency type A.

Individualized Care Delivery for Children With Autism and Related Disabilities Undergoing Overnight Video Electroencephalography (EEG): One Hospital's Experience With a Coordinated Team Approach.

Background and Purpose: Children with developmental disabilities have increased risk of epilepsy and need for overnight video electroencephalographic (EEG) monitoring. However, video EEGs have historically been considered difficult to complete for this population. An autism support service at a pediatric tertiary care hospital implemented a coordinated team approach to help children with developmental disability tolerate overnight video EEGs. The project included completion of a caregiver-report preprocedure questionnaire that then was shared with the multidisciplinary team and used to create individualized care plans. The current study aims to describe rates of video EEG completion and need for lead placement under general anesthesia among children with autism and related disabilities who received these supports. Methods: Rates of video EEG completion and general anesthesia use were analyzed for children referred to the support service between April 2019 and November 2021. Results: A total of 182 children with developmental disability (mean age = 10.3 years, 54.9% diagnosed with autism) met inclusion criteria. 92.9% (n = 169) of children successfully completed EEG (leads on ≥12 hours). Only 19.2% (n = 35) required general anesthesia for video EEG lead placement. The majority (80.2%) of parents (n = 146) completed the preprocedure questionnaire. Video EEG outcomes did not differ based on completion of the questionnaire. Parent-reported challenges with communication and cooperation were associated with shorter video EEG duration and greater use of general anesthesia. Conclusions: These findings suggest that most children with developmental disability can complete video EEG with sufficient support. Preprocedure planning can identify children who would benefit from additional accommodations. Further research is necessary to clarify which supports are most helpful.

Developmental surveillance and screening practices in a pediatric oncology clinic: Initial progress of a quality improvement study.

BACKGROUND: Pediatric cancer patients' oncology teams regularly take on a primary care role, but due to the urgent nature of cancer treatment, developmental screenings may be deprioritized. This leaves patients at risk of developmental diagnoses and referrals being delayed. AIMS: Clarify the current developmental surveillance and screening practices of one pediatric oncology team. MATERIALS AND METHODS: Researchers reviewed charts for patients (n = 66) seen at a pediatric oncology clinic in a suburban academic medical center to determine engagement in developmental screening (including functioning around related areas such as speech, neurocognition, etc.) and referrals for care in these areas. RESULTS: Developmental histories were collected from all patients through admission history and physical examination (H&P), but there was no routinized follow-up. Physicians did not conduct regular developmental screening per American Academy of Pediatrics guidelines for any patients but identified n = 3 patients with needs while the psychology team routinely surveilled all patients seen during this time (n = 41) and identified n = 18 patients as having delays. DISCUSSION: Physicians did not routinely screen for development needs beyond H&P and were inconsistent in developmental follow-up/referrals. Integrated psychologists were key in generating referrals for developmental-based care. However, many oncology patients were not seen by psychologists quickly or at all, creating a significant gap in care during a crucial developmental period. CONCLUSION: The case is made for further routinization of ongoing developmental screening in pediatric oncology care.

Genetic and phenotypic analysis of 225 Chinese children with developmental delay and/or intellectual disability using whole-exome sequencing.

Developmental delay (DD), or intellectual disability (ID) is a very large group of early onset disorders that affects 1-2% of children worldwide, which have diverse genetic causes that should be identified. Genetic studies can elucidate the pathogenesis underlying DD/ID. In this study, whole-exome sequencing (WES) was performed on 225 Chinese DD/ID children (208 cases were sequenced as proband-parent trio) who were classified into seven phenotype subgroups. The phenotype and genomic data of patients with DD/ID were further retrospectively analyzed. There were 96/225 (42.67%; 95% confidence interval [CI] 36.15-49.18%) patients were found to have causative single nucleotide variants (SNVs) and small insertions/deletions (Indels) associated with DD/ID based on WES data. The diagnostic yields among the seven subgroups ranged from 31.25 to 71.43%. Three specific clinical features, hearing loss, visual loss, and facial dysmorphism, can significantly increase the diagnostic yield of WES in patients with DD/ID (P = 0.005, P = 0.005, and P = 0.039, respectively). Of note, hearing loss (odds ratio [OR] = 1.86%; 95% CI = 1.00-3.46, P = 0.046) or abnormal brainstem auditory evoked potential (BAEP) (OR = 1.91, 95% CI = 1.02-3.50, P = 0.042) was independently associated with causative genetic variants in DD/ID children. Our findings enrich the variation spectrums of SNVs/Indels associated with DD/ID, highlight the value genetic testing for DD/ID children, stress the importance of BAEP screen in DD/ID children, and help to facilitate early diagnose, clinical management and reproductive decisions, improve therapeutic response to medical treatment.

Diagnostic yield of the chromosomal microarray analysis in turkish patients with unexplained development delay/intellectual disability(ID), autism spectrum disorders and/or multiple congenital anomalies and new clinical findings.

BACKGROUND: Chromosomal microarray analysis is an essential tool for copy number variants detection in patients with unexplained developmental delay/intellectual disability, autism spectrum disorders, and multiple congenital anomalies. The study aims to determine the clinical significance of chromosomal microarray analysis in this patient group. Another crucial aspect is the evaluation of copy number variants detected in terms of the diagnosis of patients. METHODS AND RESULTS: A Chromosomal microarray analysis was was conducted on a total of 1227 patients and phenotype-associated etiological diagnosis was established in 135 patients. Phenotype-associated copy number variants were detected in 11% of patients. Among these, 77 patients 77 (57%, 77/135) were diagnosed with well-recognized genetic syndromes and phenotype-associated copy number variants were found in 58 patients (42.9%, 58/135). The study was designed to collect data of patients in Kocaeli Derince Training and Research Hospital retrospectively. In our study, we examined 135 cases with clinically significant copy number variability among all patients. CONCLUSIONS: In this study, chromosomal microarray analysis revealed pathogenic de novo copy number variants with new clinical features. Chromosomal microarray analysis in the Turkish population has been reported in the largest patient cohort to date.

Predictability of the neurodevelopmental assessment based on the Kyoto Scale of Psychological Development 2001 at 18-24 months of corrected age and 3 years of age in identifying cognitive impairment at 6 years of age in very preterm infants: A retrospective study at a Japanese tertiary center.

BACKGROUND: It is unknown how accurately the current Japanese classification system for neurodevelopmental delay based on the assessment with the Kyoto Scale of Psychological Development (KSPD) at toddlerhood and pre-school periods predicts cognitive impairment at school age. METHODS: This single-center retrospective cohort study enrolled infants born at 22-29 weeks of gestational age. At 18-24 months of corrected age and 3 years of age, the patients were categorized according to the current Japanese criteria for neurodevelopmental delay based on their overall developmental quotient calculated using the KSPD-2001. Cognitive impairment at 6 years of age was classified according to the calculated or estimated full-scale intelligence quotient. The predictability of the current Japanese classification of neurodevelopmental delay for cognitive impairment at 6 years of age was investigated. RESULTS: Of 566 eligible patients, 364 (64 %) completed the protocol. The current classification for the neurodevelopmental delay showed significant agreement with the severity of cognitive impairment at 6 years of age. The sensitivity and specificity of the KSPD-2001-based assessment for any cognitive impairment at 6 years of age were 0.64 and 0.74 at 18-24 months of corrected age and 0.83 and 0.70 at 3 years of age. The corresponding sensitivity and specificity for moderate/severe cognitive impairment were 0.51 and 0.96 at 18-24 months of corrected age and 0.68 and 0.95 at 3 years of age. CONCLUSION: The KSPD-2001 is a useful tool to predict the severity of cognitive impairment at school age.

An innovative and collaborative method to develop a model care and service trajectory for the assessment, diagnosis, and support of children with developmental disabilities.

This paper documents an innovative research approach undertaken to co-develop an integrated assessment, diagnosis, and support service trajectory for children suspected of having a developmental disability. It employed data-driven practices and involved multiple stakeholders such as parents, professionals, managers, and researchers. It emphasized the importance of incorporating experiential knowledge adopting an integrated care and service trajectory perspective, and using an implementation science framework. The first part of this article presents the theoretical roots and the collaborative method used to co-construct the model trajectory. The second part of this article presents the results of a survey in which participating stakeholders shared their point of view on the value and impact of this approach Overall, this article provides a step-by-step operationalization of participative research in the context of public health and social services. This may help guide future initiatives to improve services for developmental disabilities in partnership with those directly concerned by these services.

Motor Impairment Referrals to an International Child Development Clinic: It is Not Always Cerebral Palsy.

BACKGROUND: The majority of the estimated 50 to 100 million children living with disability worldwide reside in low- or middle-income countries. As families migrate to avoid humanitarian crises, children with developmental disability and delay warrant particular attention in refugee and international health settings. During transitions, medical documentation may be lost and diagnoses may not be fully understood, contributing to the challenges of determining etiologies of motor impairment. METHODS: Of the first 100 refugee children who were referred to the Child Development Clinic, we identified a subset of children referred for motor impairment or cerebral palsy. Data on their presentation, diagnoses following evaluation, and therapeutic services required was collected by retrospective chart review. RESULTS: Twenty children were referred for motor impairment and cerebral palsy. Average age was 8.9 years; 45% were female. Eight children were eventually diagnosed with cerebral palsy, and 12 had alternate or inconclusive diagnoses. Microcephaly was more common in children diagnosed with cerebral palsy. CONCLUSIONS: The frequent differences between referral and final diagnoses in refugee children referred for cerebral palsy highlights the need for pediatricians' careful examination and diagnostic reasoning upon initial presentation.

Measurement of Developmental and Behavioral Concerns in Toddlers With Tuberous Sclerosis Complex.

BACKGROUND: The TAND (Tuberous Sclerosis Complex [TSC]-Associated Neuropsychiatric Disorders) Checklist was developed as a clinical screener for neurodevelopmental disorders in TSC. Most studies have described patterns in older children and adults. This study sought to better understand behavioral concerns as measured by the TAND Checklist in young children with TSC. METHODS: We examined patterns of caregiver responses to the TAND Checklist in 90 toddlers with TSC (12 to 23 months n = 60; 24 to 36 months n = 30) through data collected during baseline visits across two TSC early intervention studies. RESULTS: Over 90% of caregivers reported at least one behavioral concern related to TAND. The number of concerns increased with age. Delayed language was the most frequently reported concern across ages (12 to 23 months: 58.3%, 24 to 36 months: 86.7%). Questions related to behavioral concerns were largely relevant in this age range, but questions in other areas, such as neuropsychological or academic function, were not. CONCLUSIONS: TAND symptoms are very common in toddlers with TSC, and these symptoms may increase with age. The TAND Checklist is a useful tool for identifying behavioral concerns efficiently, but several items and sections are not suited to younger children. Results support the development of an abbreviated form of the TAND Checklist for toddlers.

Diagnostic findings and yield of investigations for children with developmental regression.

Childhood conditions that feature developmental regression are poorly understood. Phenotype-genotype characterization and diagnostic yield data are needed to inform clinical decision-making. The aim of this study was to report the conditions featuring developmental regression and assess diagnostic yields of investigations. A retrospective chart review of children presenting with developmental regression to a tertiary pediatric genetic clinic between 2018 and 2021 was performed. Of 99 children, 30% (n = 30) had intellectual disability (ID), 21% (n = 21) were autistic, 39% (n = 39) were autistic with ID, and 9% (n = 9) did not have ID or autism. Thirty-two percent (n = 32) of children received a new diagnosis, including eight molecular findings not previously reported to feature developmental regression. Of the children investigated, exome sequencing (ES) provided the highest diagnostic yield (51.1%, n = 24/47), highest (63.6%, n = 14/22) for children with ID, 50% for autistic children with ID (n = 6/12) and children without autism or ID (n = 3/6), and 14.3% (n = 1/7) for autistic children without ID. We highlight the conditions that feature developmental regression and report on novel phenotypic expansions. The high diagnostic yield of ES, regardless of autism or ID diagnosis, indicates the presence of developmental regression as an opportunity to identify the cause, including for genetic differences not previously reported to include regression.

Early onset epileptic and developmental encephalopathy and MOGS variants: a new diagnosis in the whole exome sequencing (WES) ERA : Report of a new patient and review of the literature.

Mannosyl-oligosaccharide glucosidase - congenital disorder of glycosylation (MOGS-CDG) is determined by biallelic mutations in the mannosyl-oligosaccharide glucosidase (glucosidase I) gene. MOGS-CDG is a rare disorder affecting the processing of N-Glycans (CDG type II) and is characterized by prominent neurological involvement including hypotonia, developmental delay, seizures and movement disorders. To the best of our knowledge, 30 patients with MOGS-CDG have been published so far. We described a child who is compound heterozygous for two novel variants in the MOGS gene. He presented Early Infantile Developmental and Epileptic Encephalopathy (EI-DEE) in the absence of other specific systemic involvement and unrevealing first-line biochemical findings. In addition to the previously described features, the patient presented a Hirschprung disease, never reported before in individuals with MOGS-CDG.

Preschooler Screen Time During the Pandemic Is Prospectively Associated With Lower Achievement of Developmental Milestones.

OBJECTIVE: The aim of this study was to assess the developmental risks associated with total screen time, and specifically newer mobile devices, in the context of the pandemic. METHODS: This study uses parent-reported data from a prospective cohort of Canadian preschool-age children. The exposure variable is child daily screen time measured at the age of 3.5 years categorized as light (<1 hr/d), moderate (1-4 hr/d), or intensive (>4 hr/d) use (N = 315). Time spent on mobile devices was considered separately as a continuous variable. Our outcome is child global development scores, which combine assessments of communication, cognitive, personal-social, and motor skills measured at the age of 4.5 years using the Ages and Stages Questionnaire (ASQ) (N = 249, 79% retained). ASQ scores were dichotomized to distinguish children at risk of developmental delays (below the 15th percentile) from those not at risk. We estimate associations between child screen time and later global development using multiple regressions adjusted for child sex and temperament, and parent education. We also examine whether associations are moderated by child and parent characteristics. RESULTS: Logistic regressions revealed that intensive users were more at risk of global developmental delays compared with light users (OR = 4.29, p = 0.020). Mobile device use was also associated with lower global scores (ß = -3.064; p = 0.028), but not with risk of delays. We found no evidence that associations were moderated by child sex and temperament, or parent education. CONCLUSION: The findings suggest that intensive screen time may be associated with delays in child global development. Early childhood professionals should encourage families with preschoolers to prioritize screen-free activities to promote optimal cognitive, language, social, and motor development.