Publications by authors named "K Varvagiannis"

Article Synopsis
  • The translation elongation factor eEF1A2 is crucial for binding aminoacyl-tRNA to the ribosome, and since 2012, 21 harmful variants have been linked to severe neurodevelopmental disorders, including epilepsy and intellectual disabilities.
  • A recent study gathered 26 patients with EEF1A2 variants, revealing a milder clinical profile than previously reported, with higher walking and language skills and lower rates of intellectual disability and epilepsy.
  • The research identified 8 new EEF1A2 variants and suggests that severe and moderate phenotypes are linked to specific protein regions affecting GTP exchange, while milder variants may affect secondary functions, contributing to a broader understanding
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Calmodulin-binding transcriptional activator 1 (CAMTA1) is highly expressed in the brain and plays a role in cell cycle regulation, cell differentiation, regulation of long-term memory, and initial development, maturation, and survival of cerebellar neurons. The existence of human neurological phenotypes, including cerebellar dysfunction with variable cognitive and behavioral abnormalities (CECBA), associated with CAMTA1 variants, has further supported its role in brain functions. In this study, we phenotypically and molecularly characterize the largest cohort of individuals (n = 26) with 23 novel CAMTA1 variants (frameshift-7, nonsense-6, splicing-1, initiation codon-1, missense-5, and intragenic deletions-3) and compare the findings with all previously reported cases (total = 53).

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Pathogenic variants underly O'Donnell-Luria-Rodan syndrome, a recently described neurodevelopmental disorder characterized by global developmental delay, variable degrees of intellectual disability, and subtle facial dysmorphism. Less common findings include autism, seizures, gastrointestinal (GI) problems, and abnormal head circumference. Occurrence of mostly truncating variants as well as the similar phenotype observed in individuals with deletions spanning suggest haploinsufficiency of this gene as a common mechanism for the disorder, while a gain-of-function or dominant-negative effect cannot be ruled out for some missense variants.

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