PUBLICATION

Bi-allelic variants in neuronal cell adhesion molecule cause a neurodevelopmental disorder characterized by developmental delay, hypotonia, neuropathy/spasticity

Authors
Kurolap, A., Kreuder, F., Gonzaga-Jauregui, C., Duvdevani, M.P., Harel, T., Tammer, L., Xin, B., Bakhtiari, S., Rice, J., van Eyk, C.L., Gecz, J., Mah, J.K., Atkinson, D., Cope, H., Sullivan, J.A., Douek, A.M., Colquhoun, D., Henry, J., Wlodkowic, D., Parman, Y., Candayan, A., Kocasoy-Orhan, E., Ilivitzki, A., Soudry, S., Leibu, R., Glaser, F., Sency, V., Undiagnosed Diseases Network, Ast, G., Shashi, V., Fahey, M.C., Battaloğlu, E., Jordanova, A., Meiner, V., Innes, A.M., Wang, H., Elpeleg, O., Kruer, M.C., Kaslin, J., Baris Feldman, H.
ID
ZDB-PUB-220203-10
Date
2022
Source
American journal of human genetics   109(3): 518-532 (Journal)
Registered Authors
Douek, Alon M., Kaslin, Jan
Keywords
NRCAM, hypotonia, neurodevelopmental disease, neuronal cell adhesion molecule, peripheral neuropathy, spasticity
MeSH Terms
  • Animals
  • Axons/metabolism
  • Cell Adhesion/genetics
  • Cell Adhesion Molecules/genetics
  • Cell Adhesion Molecules/metabolism
  • Cell Adhesion Molecules, Neuronal
  • Humans
  • Mice
  • Muscle Hypotonia/genetics
  • Muscle Hypotonia/metabolism
  • Muscle Spasticity/metabolism
  • Neurodevelopmental Disorders*/genetics
  • Neurodevelopmental Disorders*/metabolism
  • Peripheral Nervous System Diseases*
  • Zebrafish/genetics
  • Zebrafish/metabolism
PubMed
35108495 Full text @ Am. J. Hum. Genet.
Abstract
Cell adhesion molecules are membrane-bound proteins predominantly expressed in the central nervous system along principal axonal pathways with key roles in nervous system development, neural cell differentiation and migration, axonal growth and guidance, myelination, and synapse formation. Here, we describe ten affected individuals with bi-allelic variants in the neuronal cell adhesion molecule NRCAM that lead to a neurodevelopmental syndrome of varying severity; the individuals are from eight families. This syndrome is characterized by developmental delay/intellectual disability, hypotonia, peripheral neuropathy, and/or spasticity. Computational analyses of NRCAM variants, many of which cluster in the third fibronectin type III (Fn-III) domain, strongly suggest a deleterious effect on NRCAM structure and function, including possible disruption of its interactions with other proteins. These findings are corroborated by previous in vitro studies of murine Nrcam-deficient cells, revealing abnormal neurite outgrowth, synaptogenesis, and formation of nodes of Ranvier on myelinated axons. Our studies on zebrafish nrcamaΔ mutants lacking the third Fn-III domain revealed that mutant larvae displayed significantly altered swimming behavior compared to wild-type larvae (p < 0.03). Moreover, nrcamaΔ mutants displayed a trend toward increased amounts of α-tubulin fibers in the dorsal telencephalon, demonstrating an alteration in white matter tracts and projections. Taken together, our study provides evidence that NRCAM disruption causes a variable form of a neurodevelopmental disorder and broadens the knowledge on the growing role of the cell adhesion molecule family in the nervous system.
Genes / Markers
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Mutations / Transgenics
Human Disease / Model
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