Publications by authors named "Kathrin Blaesius"

3 Publications

  • Page 1 of 1

Altered inhibition and excitation in neocortical circuits in congenital microcephaly.

Neurobiol Dis 2019 09 15;129:130-143. Epub 2019 May 15.

Charité - Universitätsmedizin Berlin, Institute of Cell- and Neurobiology, Charitéplatz 1, 10117 Berlin, Germany; Charité - Universitätsmedizin Berlin, Center for Chronically Sick Children (Sozialpädiatrisches Zentrum, SPZ), Augustenburger Platz 1, 13353 Berlin, Germany; Charité - Universitätsmedizin Berlin, Department of Pediatric Neurology, Augustenburger Platz 1, 13353 Berlin, Germany; Berlin Institute of Health (BIH), Anna-Louisa-Karsch Strasse 2, 10178 Berlin, Germany. Electronic address:

Congenital microcephaly is highly associated with intellectual disability. Features of autosomal recessive primary microcephaly subtype 3 (MCPH3) also include hyperactivity and seizures. The disease is caused by biallelic mutations in the Cyclin-dependent kinase 5 regulatory subunit-associated protein 2 gene CDK5RAP2. In the mouse, Cdk5rap2 mutations similar to the human condition result in reduced brain size and a strikingly thin neocortex already at early stages of neurogenesis that persists through adulthood. The microcephaly phenotype in MCPH arises from a neural stem cell proliferation defect. Here, we report a novel role for Cdk5rap2 in the regulation of dendritic development and synaptogenesis of neocortical layer 2/3 pyramidal neurons. Cdk5rap2-deficient murine neurons show poorly branched dendritic arbors and an increased density of immature thin spines and glutamatergic synapses in vivo. Moreover, the excitatory drive is enhanced in ex vivo brain slice preparations of Cdk5rap2 mutant mice. Concurrently, we show that pyramidal neurons receive fewer inhibitory inputs. Together, these findings point towards a shift in the excitation - inhibition balance towards excitation in Cdk5rap2 mutant mice. Thus, MCPH3 is associated not only with a neural progenitor proliferation defect but also with altered function of postmitotic neurons and hence with altered connectivity.
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http://dx.doi.org/10.1016/j.nbd.2019.05.008DOI Listing
September 2019

Identification of a novel homozygous TRAPPC9 gene mutation causing non-syndromic intellectual disability, speech disorder, and secondary microcephaly.

Am J Med Genet B Neuropsychiatr Genet 2017 Dec 14;174(8):839-845. Epub 2017 Oct 14.

Charité - Universitätsmedizin Berlin, Institute of Neuroanatomy and Cell Biology, Berlin, Germany.

TRAPPC9 gene mutations have been linked recently to autosomal recessive mental retardation 13 (MRT13; MIM#613192) with only eight families reported world-wide. We assessed patients from two consanguineous pedigrees of Pakistani descent with non-syndromic intellectual disability and postnatal microcephaly through whole exome sequencing (WES) and cosegregation analysis. Here we report six further patients from two pedigrees with homozygous TRAPPC9 gene mutations, the novel nonsense mutation c.2065G>T (p.E689*) and the previously identified nonsense mutation c.1423C>T (p.R475*). We provide an overview of previously reported clinical features and highlight common symptoms and variability of MRT13. Common findings are intellectual disability and absent speech, and frequently microcephaly, motor delay and pathological findings on MRI including diminished cerebral white matter volume are present. Mutations in TRAPPC9 should be considered in non-syndromic autosomal recessive intellectual disability with severe speech disorder.
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http://dx.doi.org/10.1002/ajmg.b.32602DOI Listing
December 2017