Rare and typically severe motor speech disorders such as childhood apraxia of speech (CAS) and dysarthria affect about 1 in 1000 children. The genetic basis of these speech disorders is well-documented, with approximately 30% of children who undergo genomic testing receiving an explanatory genetic diagnosis. As more children with speech disorders are offered genetic testing, understanding parental views and experiences around genetic testing for their child is critical in providing effective pre- and post-test genetic counselling.
View Article and Find Full Text PDFThe study of ecosystems, both natural and artificial, has historically been mediated by population dynamics theories. In this framework, quantifying population numbers and related variables (associated with metabolism or biological-environmental interactions) plays a central role in measuring and predicting system-level properties. As we move toward advanced technological engineering of cells and organisms, the possibility of bioengineering ecosystems (from the gut microbiome to wildlands) opens several questions that will require quantitative models to find answers.
View Article and Find Full Text PDFBackground: Conversations about prognosis for genetic neurodevelopmental conditions are becoming more frequent; however, there is a lack of evidence and guidance on how to approach these conversations and frame the information being provided.
Objective: (1) To understand how parents perceive prognostic conversations with healthcare professionals and their preferences for these conversations, (2) To investigate the framing of prognostic information found online.
Methods: This was a mixed-methods study, comprising of (1) a thematic analysis of interviews with parents and (2) a quantification of prognostic information available on the internet that portrayed a negative message.
This study describes a protocol to assess a novel workflow called Epi-Genomic Newborn Screening (EpiGNs) on 100,000 infants from the state of Victoria, Australia. The workflow uses a first-tier screening approach called methylation-specific quantitative melt analysis (MS-QMA), followed by second and third tier testing including targeted methylation and copy number variation analyzes with droplet digital PCR, EpiTYPER system and low-coverage whole genome sequencing. EpiGNs utilizes only two 3.
View Article and Find Full Text PDFPurpose: This study aims to comprehensively delineate the phenotypic spectrum of ACTL6B-related disorders, previously associated with both autosomal recessive and autosomal dominant neurodevelopmental disorders. Molecularly, the role of the nucleolar protein ACTL6B in contributing to the disease has remained unclear.
Methods: We identified 105 affected individuals, including 39 previously reported cases, and systematically analysed detailed clinical and genetic data for all individuals.
Background: There are no established guidelines for the follow up of infants born after a prenatal diagnosis of a genomic copy number variant (CNV), despite their increased risk of developmental issues. The aims of this study were (i) to determine the perinatal outcomes of fetuses diagnosed with and without a CNV, and (ii) to establish a population-based paediatric cohort for long term developmental follow up.
Methods: An Australian state-wide research database was screened for pregnant individuals who had a prenatal chromosomal microarray (CMA) between 2013-2019 inclusive.
Objectives: Purine-rich element-binding protein alpha (PURA) regulates gene expression and is ubiquitously expressed with an enrichment in neural tissues. Pathogenic variants in cause the neurodevelopmental disorder PURA syndrome that has a variable phenotype but typically comprises moderate-to-severe global developmental delay, intellectual disability, early-onset hypotonia and hypothermia, epilepsy, feeding difficulties, movement disorders, and subtle facial dysmorphism. Speech is reportedly absent in most, but the specific linguistic phenotype is not well described.
View Article and Find Full Text PDFBackground: Variants in GABRB2, encoding the β2 subunit of the γ-aminobutyric acid type A (GABA) receptor, can result in a diverse range of conditions, ranging from febrile seizures to severe developmental and epileptic encephalopathies. However, the mechanisms underlying the risk of developing milder vs more severe forms of disorder remain unclear. In this study, we conducted a comprehensive genotype-phenotype correlation analysis in a cohort of individuals with GABRB2 variants.
View Article and Find Full Text PDFThe application of genomics has greatly increased the diagnosis of specific monogenic causes of intellectual disability and improved our understanding of the neuronal processes that result in cognitive impairment. Meanwhile, families are building rare disease communities and seeking disease-specific treatments to change the trajectory of health and developmental outcomes for their children. To date, treatments for intellectual disability have focussed on metabolic disorders, where early treatment has improved cognition and neurodevelopmental outcomes.
View Article and Find Full Text PDFMicrobial communities often exhibit more than one possible stable composition for the same set of external conditions. In the human microbiome, these persistent changes in species composition and abundance are associated with health and disease states, but the drivers of these alternative stable states remain unclear. Here we experimentally demonstrate that a cross-kingdom community, composed of six species relevant to the respiratory tract, displays four alternative stable states each dominated by a different species.
View Article and Find Full Text PDFDev Med Child Neurol
November 2024
Observational studies have a critical role in disability research, providing the opportunity to address a range of research questions. Over the past decades, there have been substantial shifts and developments in statistical methods for observational studies, most notably for causal inference. In this review, we provide an overview of modern design and analysis concepts critical for observational studies, drawing examples from the field of disability research and highlighting the challenges in this field, to inform the readership on important statistical considerations for their studies.
View Article and Find Full Text PDFIntroduction: Newborn bloodspot screening (NBS) is a highly successful public health programme that uses biochemical and other assays to screen for severe but treatable childhood-onset conditions. Introducing genomic sequencing into NBS programmes increases the range of detectable conditions but raises practical and ethical issues. Evidence from prospectively ascertained cohorts is required to guide policy and future implementation.
View Article and Find Full Text PDFThis study aimed to determine the diagnostic yield of singleton exome sequencing and subsequent research-based trio exome analysis in children with a spectrum of brain malformations seen commonly in clinical practice. We recruited children ≤ 18 years old with a brain malformation diagnosed by magnetic resonance imaging and consistent with an established list of known genetic causes. Patients were ascertained nationally from eight tertiary paediatric centres as part of the Australian Genomics Brain Malformation Flagship.
View Article and Find Full Text PDFThe Mendelian disorders of chromatin machinery (MDCMs) represent a distinct subgroup of disorders that present with neurodevelopmental disability. The chromatin machinery regulates gene expression by a range of mechanisms, including by post-translational modification of histones, responding to histone marks, and remodelling nucleosomes. Some of the MDCMs that impact on histone modification may have potential therapeutic interventions.
View Article and Find Full Text PDFAm J Med Genet B Neuropsychiatr Genet
September 2024
Pathogenic variants in DDX3X are associated with neurodevelopmental disorders. Communication impairments are commonly reported, yet specific speech and language diagnoses have not been delineated, preventing prognostic counseling and targeted therapies. Here, we characterized speech and language in 38 female individuals, aged 1.
View Article and Find Full Text PDFSevere speech disorders lead to poor literacy, reduced academic attainment and negative psychosocial outcomes. As early as the 1950s, the familial nature of speech disorders was recognized, implying a genetic basis; but the molecular genetic basis remained unknown. In 2001, investigation of a large three generational family with severe speech disorder, known as childhood apraxia of speech (CAS), revealed the first causative gene; FOXP2.
View Article and Find Full Text PDFPathogenic variants in BRPF1 cause intellectual disability, ptosis and facial dysmorphism. Speech and language deficits have been identified as a manifestation of BRPF1-related disorder but have not been systematically characterized. We provide a comprehensive delineation of speech and language abilities in BRPF1-related disorder and expand the phenotype.
View Article and Find Full Text PDFPathogenic variants in multiple genes on the X chromosome have been implicated in syndromic and non-syndromic intellectual disability disorders. ZFX on Xp22.11 encodes a transcription factor that has been linked to diverse processes including oncogenesis and development, but germline variants have not been characterized in association with disease.
View Article and Find Full Text PDFWith increasing gene discoveries for severe speech disorders, genomic testing can alter the diagnostic and clinical paradigms, enabling better life outcomes for children and their families. However, evidence on the value of the outcomes generated is lacking, impeding optimal translation into health care. This study aims to estimate the value and uptake of genomic testing for severe childhood speech disorders.
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