Microtubule associated proteins (MAPs) are widely expressed in the central nervous system, and have established roles in cell proliferation, myelination, neurite formation, axon specification, outgrowth, dendrite, and synapse formation. We report eleven individuals from seven families harboring predicted pathogenic biallelic, de novo, and heterozygous variants in the NAV3 gene, which encodes the microtubule positive tip protein neuron navigator 3 (NAV3). All affected individuals have intellectual disability (ID), microcephaly, skeletal deformities, ocular anomalies, and behavioral issues. In mouse brain, Nav3 is expressed throughout the nervous system, with more prominent signatures in postmitotic, excitatory, inhibiting, and sensory neurons. When overexpressed in HEK293T and COS7 cells, pathogenic variants impaired NAV3 ability to stabilize microtubules. Further, knocking-down nav3 in zebrafish led to severe morphological defects, microcephaly, impaired neuronal growth, and behavioral impairment, which were rescued with co-injection of WT NAV3 mRNA and not by transcripts encoding the pathogenic variants. Our findings establish the role of NAV3 in neurodevelopmental disorders, and reveal its involvement in neuronal morphogenesis, and neuromuscular responses.

• MeSH
• Cercopithecus aethiops MeSH
• COS buňky MeSH
• dánio pruhované genetika   MeSH
• dítě MeSH
• HEK293 buňky MeSH
• lidé MeSH
• mentální retardace * genetika   MeSH
• mikrocefalie * genetika   patologie   MeSH
• myši MeSH
• neurony metabolismus   patologie   MeSH
• předškolní dítě MeSH
• proteiny asociované s mikrotubuly genetika   metabolismus   MeSH
• proteiny nervové tkáně genetika   metabolismus   MeSH
• vývojové poruchy u dětí * genetika   MeSH
• zvířata MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mužské pohlaví MeSH
• myši MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• NAV3 protein, human MeSH Prohlížeč
• proteiny asociované s mikrotubuly MeSH
• proteiny nervové tkáně MeSH

Stormorken syndrome is a multiorgan hereditary disease caused by dysfunction of the endoplasmic reticulum (ER) Ca2+ sensor protein STIM1, which forms the Ca2+ release-activated Ca2+ (CRAC) channel together with the plasma membrane channel Orai1. ER Ca2+ store depletion activates STIM1 by releasing the intramolecular "clamp" formed between the coiled coil 1 (CC1) and CC3 domains of the protein, enabling the C terminus to extend and interact with Orai1. The most frequently occurring mutation in patients with Stormorken syndrome is R304W, which destabilizes and extends the STIM1 C terminus independently of ER Ca2+ store depletion, causing constitutive binding to Orai1 and CRAC channel activation. We found that in cis deletion of one amino acid residue, Glu296 (which we called E296del) reversed the pathological effects of R304W. Homozygous Stim1 E296del+R304W mice were viable and phenotypically indistinguishable from wild-type mice. NMR spectroscopy, molecular dynamics simulations, and cellular experiments revealed that although the R304W mutation prevented CC1 from interacting with CC3, the additional deletion of Glu296 opposed this effect by enabling CC1-CC3 binding and restoring the CC domain interactions within STIM1 that are critical for proper CRAC channel function. Our results provide insight into the activation mechanism of STIM1 by clarifying the molecular basis of mutation-elicited protein dysfunction and pathophysiology.

• MeSH
• abnormální erytrocyty MeSH
• aminokyseliny metabolismus   MeSH
• dyslexie MeSH
• endoplazmatické retikulum metabolismus   MeSH
• ichtyóza MeSH
• kanály aktivované uvolněním vápníku * genetika   MeSH
• membránové proteiny * metabolismus   MeSH
• migréna MeSH
• mióza MeSH
• mutace MeSH
• myši MeSH
• protein ORAI1 metabolismus   MeSH
• protein STIM1 genetika   MeSH
• slezina abnormality   MeSH
• svalová únava MeSH
• trombocytopatie MeSH
• vápník metabolismus   MeSH
• vápníkové kanály metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• aminokyseliny MeSH
• kanály aktivované uvolněním vápníku * MeSH
• membránové proteiny * MeSH
• protein ORAI1 MeSH
• protein STIM1 MeSH
• Stim1 protein, mouse MeSH Prohlížeč
• vápník MeSH
• vápníkové kanály MeSH

We report two unrelated patients with overlapping chromosome 2q13 deletions (patient 1 in chr2:111415137-113194067 bp and patient 2 in chr2:110980342-113007823 bp, hg 19). Patient 1 presents with developmental delay, microcephaly and mild dysmorphic facial features, and patient 2 with autism spectrum disorder, borderline cognitive abilities, deficits in attention and executive functions and mild dysmorphic facial features. The mother and maternal grandmother of patient 1 were healthy carriers of the deletion. Previously, 2q13 deletions were reported in 27 patients, and the interpretation of its clinical significance varied. Our findings support that the 2q13 deletion is associated with a developmental delay syndrome manifesting with variable expressivity and reduced penetrance which poses a challenge for genetic counselling as well as the clinical recognition of 2q13 deletion patients.

• Klíčová slova
• 2q13 deletion, BCL2L11, Developmental delay, FBLN7, Facial dysmorphism, TMEM87B, aCGH,
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH