A20 haploinsufficiency (HA20) is an autoinflammatory disease caused by heterozygous loss-of-function variations in , the gene encoding the A20 protein. Diagnosis of HA20 is challenging due to its heterogeneous clinical presentation and the lack of pathognomonic symptoms. While the pathogenic effect of truncating variations is clearly established, that of missense variations is difficult to determine. Herein, we identified a novel variation, p.(Leu236Pro), located in the A20 ovarian tumor (OTU) domain and demonstrated its pathogenicity. In the patients' primary cells, we observed reduced A20 levels. Protein destabilization was predicted in silico for A20_Leu236Pro and enhanced proteasomal degradation was confirmed in vitro through a flow cytometry-based functional assay. By applying this approach to the study of another missense variant, A20_Leu275Pro, for which no functional characterization has been performed to date, we showed that this variant also undergoes enhanced proteasomal degradation. Moreover, we showed a disrupted ability of A20_Leu236Pro to inhibit the NF-κB pathway and to deubiquitinate its substrate TRAF6. Structural modeling revealed that two residues involved in OTU pathogenic missense variations (i.e. Glu192Lys and Cys243Tyr) establish common interactions with Leu236. Interpretation of newly identified missense variations is challenging, requiring, as illustrated here, functional demonstration of their pathogenicity. Together with functional studies, in silico structure analysis is a valuable approach that allowed us (i) to provide a mechanistic explanation for the haploinsufficiency resulting from missense variations and (ii) to unveil a region within the OTU domain critical for A20 function.
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http://dx.doi.org/10.7554/eLife.81280 | DOI Listing |
Neurology
February 2025
Department of Integrated Traditional Chinese and Western Medicine, The Third Affiliated Hospital of Soochow University, Changzhou, China.
Background And Objectives: Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme that regulates folate and homocysteine metabolism. Genetic variation in has been implicated in cerebrovascular disease risk, although research in diverse populations is lacking. We thus aimed to investigate the effect of genetically predicted MTHFR activity on risk of ischemic stroke (IS) and its main subtypes using a multiancestry Mendelian randomization (MR) approach.
View Article and Find Full Text PDFIntegr Biol (Camb)
January 2025
Manipal Academy of Higher Education (MAHE), Manipal 576104, Karnataka, India.
The role of GTF2I (General Transcription Factor2I) alteration has already been reported in thymic cancer as a valuable biomarker. However, the association of GTF2I mutation with renal cancer for prognosis of immunotherapy is not yet examined. The biologic and oncologic significance of GTF2I in renal cancer was examined at multiomics level such as mutation, copy number alteration, structural variants.
View Article and Find Full Text PDFBiol Res
January 2025
Department of Pediatrics, The First Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China.
Background: Karyotype 46, XY female disorders of sex development (46, XY female DSD) are congenital conditions due to irregular gonadal development or androgen synthesis or function issues. Genes significantly influence DSD; however, the underlying mechanisms remain unclear. This study identified a Chinese family with 46, XY female DSD due to the CUL4B gene.
View Article and Find Full Text PDFInt J Mol Sci
December 2024
Neurological Disorder Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation, Doha P.O. Box 5825, Qatar.
Deficits in social communication, restricted interests, and repetitive behaviours are hallmarks of autism spectrum disorder (ASD). Despite high genetic heritability, the majority of clinically diagnosed ASD cases have unknown genetic origins. We performed genome sequencing on mothers, fathers, and affected individuals from 104 families with ASD in Oman, a Middle Eastern country underrepresented in international genetic studies.
View Article and Find Full Text PDFGenes (Basel)
December 2024
Receptor Biology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA.
Neuroligins (NLGNs) are postsynaptic adhesion molecules critical for neuronal development that are highly associated with autism spectrum disorder (ASD). Here, we provide an overview of the literature on rare variants. In addition, we introduce a new approach to analyze human variation within genes to identify sensitive regions that have an increased frequency of ASD-associated variants to better understand NLGN function.
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