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Sphingomyelinases generate ceramide from sphingomyelin as a second messenger in intracellular signaling pathways involved in cell proliferation, differentiation, or apoptosis. Children from 12 unrelated families presented with microcephaly, simplified gyral pattern of the cortex, hypomyelination, cerebellar hypoplasia, congenital arthrogryposis, and early fetal/postnatal demise. Genomic analysis revealed bi-allelic loss-of-function variants in SMPD4, coding for the neutral sphingomyelinase-3 (nSMase-3/SMPD4). Overexpression of human Myc-tagged SMPD4 showed localization both to the outer nuclear envelope and the ER and additionally revealed interactions with several nuclear pore complex proteins by proteomics analysis. Fibroblasts from affected individuals showed ER cisternae abnormalities, suspected for increased autophagy, and were more susceptible to apoptosis under stress conditions, while treatment with siSMPD4 caused delayed cell cycle progression. Our data show that SMPD4 links homeostasis of membrane sphingolipids to cell fate by regulating the cross-talk between the ER and the outer nuclear envelope, while its loss reveals a pathogenic mechanism in microcephaly.
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http://dx.doi.org/10.1016/j.ajhg.2019.08.006 | DOI Listing |
Reprod Domest Anim
September 2025
Institute of Genetics, Vetsuisse Faculty, University of Bern, Bern, Switzerland.
Dystocia due to developmental disorders causing foetal malformation is a significant challenge in bovine obstetrics, often resulting in severe birth complications. This narrative review provides an updated overview of the most common congenital syndromes associated with dystocia in cattle, emphasising both their clinical implications and underlying causes. Congenital disorders such as schistosoma reflexum, perosomus elumbis, arthrogryposis, hydrocephalus, anasarca and embryonic duplication are reviewed in detail, along with their impact on the course of calving.
View Article and Find Full Text PDFMedicine (Baltimore)
August 2025
Department of Neonatology, Hangzhou Women's Hospital, Hangzhou, Zhejiang Province, China.
Rationale: Contractures, pterygia, and spondylocarpotarsal fusion syndrome (CPSFS) comprises a group of extremely rare genetic disorders characterized by congenital craniofacial and musculoskeletal abnormalities. With fewer than 500 cases reported globally, this scarcity contributes to limited clinical recognition, frequent diagnostic delays or errors, and missed opportunities for timely intervention. We present this case to enhance awareness of CPSFS and report a novel pathogenic variant in MYH3 (previously undocumented in the literature) that broadens the known mutational spectrum of MYH3 and enriches the phenotypic profile of CPSFS.
View Article and Find Full Text PDFNeuromuscul Disord
July 2025
Centre for Neuromuscular Diseases, Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, UK.
Arthrogryposis multiplex congenita (AMC) is associated with >150 genes, including ADGRG6, which codes for an adhesion G protein-coupled receptor. Biallelic loss of function variants in ADGRG6 have been linked to lethal congenital contracture syndrome. Here we present an atypical, milder phenotype associated with a novel ADGRG6 variant.
View Article and Find Full Text PDFOrphanet J Rare Dis
July 2025
Department of Obstetrics and Gynaecology, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, the Netherlands.
Background: Pre-pregnancy counselling in women with Arthrogryposis Multiplex Congenita (AMC) is not implemented as standard care. Prior surveys revealed that the majority of adults with AMC live independently with or without support, are working, and engage in social actifities. Although many of them underwent pregnancies, literature is scarce concerning women with AMC and pregnancies.
View Article and Find Full Text PDFBMC Pediatr
July 2025
Faculty of Medical Sciences, Lebanese University, Beirut, Lebanon.
Background: CEBALID syndrome (Craniofacial defects, dysmorphic Ears, Brain Abnormalities, Language delay, and Intellectual Disability) is caused by C-terminal truncated transcriptional activator MN1. This novel syndrome characterized by neurodevelopmental delay, craniofacial anomalies, and partial rhombencephalosynapsis was recently identified in 2020. Since then, less than 30 cases have been reported worldwide.
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