30 research outputs found
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A novel nonsense variant in the NFE2L1 transcription factor in a patient with developmental delay, hypotonia, genital anomalies, and failure to thrive
The NFE2L1 transcription factor (also known as Nrf1 for nuclear factor erythroid 2-related factor-1) is a broadly expressed basic leucine zipper protein that performs a critical role in the cellular stress response pathway. Here, we identified a heterozygous nonsense mutation located in the last exon of the gene that terminates translation prematurely, resulting in the production of a truncated peptide devoid of the carboxyl-terminal region containing the DNA-binding and leucine-zipper dimerization interface of the protein. Variant derivatives were well expressed in vitro, and they inhibited the transactivation function of wild-type proteins in luciferase reporter assays. Our studies suggest that this dominant-negative effect of truncated variants is through the formation of inactive heterodimers with wild-type proteins preventing the expression of its target genes. These findings suggest the potential role of diminished NFE2L1 function as an explanation for the developmental delay, hypotonia, hypospadias, bifid scrotum, and failure to thrive observed in the patient
A phenotypically severe, biochemically “silent” case of HIBCH deficiency in a newborn diagnosed by rapid whole exome sequencing and enzymatic testing
3-Hydroxyisobutyryl-CoA dehydrogenase (HIBCH) deficiency is a rare error in valine catabolism associated with a Leigh syndrome-like phenotype, mitochondrial dysfunction, and increased C4-OH. We report the most severe case to date in a full-term female who presented with poor feeding and nystagmus on day of life (DOL) 1. Although initial neuroimaging findings were concerning for metabolic disease, further metabolic testing was nondiagnostic and she was discharged on DOL 18. She was readmitted on DOL 22 after severe apneic episodes requiring intubation, with EEG demonstrating multifocal seizures and MRI/MRS demonstrating worsening findings. Care was withdrawn DOL 27 and she expired. Rapid whole exome sequencing (WES) demonstrated compound heterozygous variants in HIBCH with a paternal pathogenic variant (c.852delA, p.L284FfsX10) and a maternal likely pathogenic variant (c.488G>T, p.C163F). Fibroblast enzymatic testing demonstrated marked reduction in HIBCH levels. This case demonstrates the importance of rapid WES and follow-up functional testing in establishing a diagnosis when metabolic disease is suspected but lacks an expected biochemical signature
Reconciling newborn screening and a novel splice variant in BTD
Here, we report a newborn female infant from the well-baby cohort of the BabySeq Project who was identified with compound heterozygous BTD gene variants. The two identified variants included a well-established pathogenic variant (c.1612C>T, p.Arg538Cys) that causes profound biotinidase deficiency (BTD) in homozygosity. In addition, a novel splice variant (c.44+1G>A, p.?) was identified in the invariant splice donor region of intron 1, potentially predictive of loss of function. The novel variant was predicted to impact splicing of exon 1; however, given the absence of any reported pathogenic variants in exon 1 and the presence of alternative splicing with exon 1 absent in most tissues in the GTEx database, we assigned an initial classification of uncertain significance. Follow-up medical record review of state-mandated newborn screen (NBS) results revealed an initial out-of-range biotinidase activity level. Levels from a repeat NBS sample barely passed cutoff into the normal range. To determine whether the infant was biotinidase-deficient, subsequent diagnostic enzyme activity testing was performed, confirming partial BTD, and resulted in a change of management for this patient. This led to reclassification of the novel splice variant based on these results. In conclusion, combining the genetic and NBS results together prompted clinical follow-up that confirmed partial BTD and informed this novel splice site's reclassification, emphasizing the importance of combining iterative genetic and phenotypic evaluations
Quality improvement: The tools we need to improve care for patients with inborn errors of metabolism
A β-Peptide Agonist of the GLP-1 Receptor, a Class B GPCR
[Image: see text] Previous work has shown that certain β(3)-peptides can effectively mimic the side chain display of an α-helix and inhibit interactions between proteins, both in vitro and in cultured cells. Here we describe a β(3)-peptide analog of GLP-1, CC-3(Act), that interacts with the GLP-1R extracellular domain (nGLP-1R) in vitro in a manner that competes with exendin-4 and induces GLP-1R-dependent cAMP signaling in cultured CHO-K1 cells expressing GLP-1R
Integrating Science-Based Co-management, Partnerships, Participatory Processes and Stewardship Incentives to Improve the Performance of Small-Scale Fisheries
Small scale fisheries are critically important for the provision of food security, livelihoods, and economic development for billions of people. Yet, most of these fisheries appear to not be achieving either fisheries or conservation goals, with respect to creating healthier oceans that support more fish, feed more people and improve livelihoods. Research and practical experience have elucidated many insights into how to improve the performance of small-scale fisheries. Here, we present lessons learned from five case studies of small-scale fisheries in Cuba, Mexico, the Philippines, and Belize. The major lessons that arise from these cases are: (1) participatory processes empower fishers, increase compliance, and support integration of local and scientific knowledge; (2) partnership across sectors improves communication and community buy-in; (3) scientific analysis can lead fishery reform and be directly applicable to co-management structures. These case studies suggest that a fully integrated approach that implements a participatory process to generate a scientific basis for fishery management (e.g., data collection, analysis, design) and to design management measures among stakeholders will increase the probability that small-scale fisheries will implement science-based management and improve their performance