Background: The absence of standardized approaches for handling genetic test results in electronic health records (EHRs), combined with a lack of diagnostic codes for most rare disorders, hinders accurate and timely identification of patients with rare genetic variants. This impedes access to research opportunities and genomic-driven care. To reduce the diagnostic odyssey, identify research-eligible subjects, and ultimately enhance patient care, it is critical to optimize approaches to retrieve genetic results.
View Article and Find Full Text PDFWhole-genome sequencing (WGS) as a diagnostic test offers children suspected of having a rare genetic condition and their families the best direct path toward securing a precise genetic diagnosis (PrGD). Yet, a limited supply and inequitable access to genetic services are impediments to realizing the benefits of a PrGD. Such access disparities might be due to a range of structural and social determinants that manifest in interactions, or the lack thereof, between families, providers, and institutions.
View Article and Find Full Text PDFAim: To identify the behavioral correlates of caregiver-reported oral health of individuals with Joubert Syndrome (JS).
Methods: This cross-sectional study included 302 caregivers of individuals with JS from the JS registry who responded to a 56-item REDCap survey, and a purposive subset of 30 participants with JS for which a dental screening was completed. The primary outcome was caregiver-reported oral health of individuals with JS (good/very good vs.
The prefrontal cortex (PFC) is critical for myriad high-cognitive functions and is associated with several neuropsychiatric disorders. Here, using Patch-seq and single-nucleus multiomic analyses, we identified genes and regulatory networks governing the maturation of distinct neuronal populations in the PFC of rhesus macaque. We discovered that specific electrophysiological properties exhibited distinct maturational kinetics and identified key genes underlying these properties.
View Article and Find Full Text PDFBackground: Decisions to split two or more phenotypic manifestations related to genetic variations within the same gene can be challenging, especially during the early stages of syndrome discovery. Genotype-based diagnostics with artificial intelligence (AI)-driven approaches using next-generation phenotyping (NGP) and DNA methylation (DNAm) can be utilized to expedite syndrome delineation within a single gene.
Methods: We utilized an expanded cohort of 56 patients (22 previously unpublished individuals) with truncating variants in the MN1 gene and attempted different methods to assess plausible strategies to objectively delineate phenotypic differences between the C-Terminal Truncation (CTT) and N-Terminal Truncation (NTT) groups.
Newborn genomic sequencing (NBSeq) has the potential to substantially improve early detection of rare genetic conditions, allowing for pre-symptomatic treatment to optimize outcomes. Expanding conceptions of the clinical utility of NBSeq include earlier access to behavioral early intervention to support the acquisition of core motor, cognitive, communication, and adaptive skills during critical windows in early development. However, important questions remain about equitable access to early intervention programs for the growing number of infants identified with a genetic condition via NBSeq.
View Article and Find Full Text PDFRhombencephalosynapsis (RES) is a hindbrain malformation characterized by a missing cerebellar vermis with apposition or fusion of the cerebellar hemispheres. The present clinical case report provides a comprehensive, longitudinal overview of cognitive and affective manifestations in a 22-year-old patient with RES. The patient shows clinical signs of emotional reactivity and dysregulation, impulsivity, and impairments in executive functioning since early childhood.
View Article and Find Full Text PDFThe prefrontal cortex (PFC) is critical for myriad high-cognitive functions and is associated with several neuropsychiatric disorders. Here, using Patch-seq and single-nucleus multiomic analyses, we identified genes and regulatory networks governing the maturation of distinct neuronal populations in the PFC of rhesus macaque. We discovered that specific electrophysiological properties exhibited distinct maturational kinetics and identified key genes underlying these properties.
View Article and Find Full Text PDFDebates about the ethics of human brain organoids have proceeded without the input of individuals whose brains are being modeled. Interviews with donors of biospecimens for brain organoid research revealed overall enthusiasm for brain organoids as a tool for biomedical discovery, alongside a desire for ongoing engagement with research teams to learn the results of the research, to allow transfer of decision-making authority over time, and to ensure ethical boundaries are not crossed. Future work is needed to determine the most feasible and resource-efficient way to longitudinally engage donors participating in brain organoid research.
View Article and Find Full Text PDFBackground: Joubert syndrome (JS) is a neurodevelopmental ciliopathy characterised by a distinctive mid-hindbrain malformation, the 'molar tooth sign'. Over 40 JS-associated genes are known, accounting for two-thirds of cases.
Methods: While most variants are novel or extremely rare, we report on 11 recurring variants in seven genes, including three known 'founder variants' in the Ashkenazi Jewish, Hutterite and Finnish populations.
Unlabelled: This is the first case report of sleep-disordered breathing in patients with pontine tegmental cap dysplasia, a very rare neurological disorder characterized by an anatomic malformation in the pons. Patients present with hypotonia, cognitive dysfunction, and cranial nerve palsies (eg, hearing loss, trigeminal anesthesia, and swallow dysfunction). Extensive studies have demonstrated the relevance of different pontine neuronal nuclei in breathing regulation, which are structurally abnormal in pontine tegmental cap dysplasia.
View Article and Find Full Text PDFDysfunction of the primary cilium, a microtubule-based signaling organelle, leads to genetic conditions called ciliopathies. Hedgehog (Hh) signaling is mediated by the primary cilium in vertebrates and is therefore implicated in ciliopathies; however, it is not clear which immortal cell lines are the most appropriate for modeling pathway response in human disease; therefore, we systematically evaluated Hh in five commercially available, immortal mammalian cell lines: ARPE-19, HEK293T, hTERT RPE-1, NIH/3T3, and SH-SY5Y. Under proper conditions, all of the cell lines ciliated adequately for our subsequent experiments, except for SH-SY5Y which were excluded from further analysis.
View Article and Find Full Text PDFAm J Med Genet A
August 2022
Joubert syndrome (JS), a well-established ciliopathy, is characterized by the distinctive molar tooth sign on brain MRI, ataxia, and neurodevelopmental features. Other manifestations can include polydactyly, accessory frenula, renal, or liver disease. Here, we report individuals meeting criteria for JS with de novo heterozygous variants in SLC30A7 (Chr1p21.
View Article and Find Full Text PDFAnnu Rev Genomics Hum Genet
August 2022
The Joubert syndrome (JS), Meckel syndrome (MKS), and nephronophthisis (NPH) ciliopathy spectrum could be the poster child for advances and challenges in Mendelian human genetics over the past half century. Progress in understanding these conditions illustrates many core concepts of human genetics. The JS phenotype alone is caused by pathogenic variants in more than 40 genes; remarkably, all of the associated proteins function in and around the primary cilium.
View Article and Find Full Text PDFPurpose: Genome-wide sequencing is increasingly being performed during pregnancy to identify the genetic cause of congenital anomalies. The interpretation of prenatally identified variants can be challenging and is hampered by our often limited knowledge of prenatal phenotypes. To better delineate the prenatal phenotype of Coffin-Siris syndrome (CSS), we collected clinical data from patients with a prenatal phenotype and a pathogenic variant in one of the CSS-associated genes.
View Article and Find Full Text PDFStem Cell Reports
December 2021
Research using human fetal tissue has saved millions of lives through vaccines and other advances, but was markedly restricted by federal regulations in 2019. Although the restrictions were partially reversed in 2021, additional regulatory changes are needed to prevent further damage to essential research programs while preserving protection for human subjects.
View Article and Find Full Text PDFBackground: Joubert syndrome (JS) is a recessively inherited ciliopathy characterised by congenital ocular motor apraxia (COMA), developmental delay (DD), intellectual disability, ataxia, multiorgan involvement, and a unique cerebellar and brainstem malformation. Over 40 JS-associated genes are known with a diagnostic yield of 60%-75%.In 2018, we reported homozygous hypomorphic missense variants of the gene in two families with mild JS.
View Article and Find Full Text PDFAm J Med Genet A
January 2022
Primary ciliopathies are heterogenous disorders resulting from perturbations in primary cilia form and/or function. Primary cilia are cellular organelles which mediate key signaling pathways during development, such as the sonic hedgehog (SHH) pathway which is required for neuroepithelium and central nervous system development. Joubert syndrome is a primary ciliopathy characterized by cerebellar/brain stem malformation, hypotonia, and developmental delays.
View Article and Find Full Text PDFAm J Hum Genet
August 2021
Despite widespread clinical genetic testing, many individuals with suspected genetic conditions lack a precise diagnosis, limiting their opportunity to take advantage of state-of-the-art treatments. In some cases, testing reveals difficult-to-evaluate structural differences, candidate variants that do not fully explain the phenotype, single pathogenic variants in recessive disorders, or no variants in genes of interest. Thus, there is a need for better tools to identify a precise genetic diagnosis in individuals when conventional testing approaches have been exhausted.
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