Abstract
Corpus callosum malformations are associated with a broad range of neurodevelopmental diseases. We report that de novo mutations in MAST1 cause mega-corpus-callosum syndrome with cerebellar hypoplasia and cortical malformations (MCC-CH-CM) in the absence of megalencephaly. We show that MAST1 is a microtubule-associated protein that is predominantly expressed in post-mitotic neurons and is present in both dendritic and axonal compartments. We further show that Mast1 null animals are phenotypically normal, whereas the deletion of a single amino acid (L278del) recapitulates the distinct neurological phenotype observed in patients. In animals harboring Mast1 microdeletions, we find that the PI3K/AKT3/mTOR pathway is unperturbed, whereas Mast2 and Mast3 levels are diminished, indicative of a dominant-negative mode of action. Finally, we report that de novo MAST1 substitutions are present in patients with autism and microcephaly, raising the prospect that mutations in this gene give rise to a spectrum of neurodevelopmental diseases.
Keywords:
MAST1; cerebellar hypoplasia; corpus callosum; microdeletion; microtubules.
Copyright © 2018 Elsevier Inc. All rights reserved.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, Non-U.S. Gov't
MeSH terms
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Agenesis of Corpus Callosum / complications
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Agenesis of Corpus Callosum / diagnostic imaging
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Agenesis of Corpus Callosum / genetics*
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Agenesis of Corpus Callosum / pathology
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Animals
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Animals, Newborn
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Apoptosis / genetics
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Brain / metabolism
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Brain / pathology
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Cells, Cultured
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Cerebellum / abnormalities*
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Cerebellum / diagnostic imaging
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Child
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Developmental Disabilities / complications
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Developmental Disabilities / diagnostic imaging
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Developmental Disabilities / genetics
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Disease Models, Animal
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Embryo, Mammalian
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Female
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Gene Expression Regulation, Developmental / genetics*
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Humans
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Male
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Malformations of Cortical Development / complications
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Malformations of Cortical Development / diagnostic imaging
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Malformations of Cortical Development / genetics*
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Mice
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Mice, Inbred C57BL
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Mice, Knockout
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Microtubule-Associated Proteins / deficiency
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Microtubule-Associated Proteins / genetics*
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Mutation / genetics*
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Nerve Tissue Proteins / metabolism
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Nervous System Malformations / complications
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Nervous System Malformations / diagnostic imaging
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Nervous System Malformations / genetics*
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PAX6 Transcription Factor / metabolism
Substances
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Microtubule-Associated Proteins
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Nerve Tissue Proteins
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PAX6 Transcription Factor