Deficiency of asparagine synthetase causes congenital microcephaly and a progressive form of encephalopathy.

Journal Article

We analyzed four families that presented with a similar condition characterized by congenital microcephaly, intellectual disability, progressive cerebral atrophy, and intractable seizures. We show that recessive mutations in the ASNS gene are responsible for this syndrome. Two of the identified missense mutations dramatically reduce ASNS protein abundance, suggesting that the mutations cause loss of function. Hypomorphic Asns mutant mice have structural brain abnormalities, including enlarged ventricles and reduced cortical thickness, and show deficits in learning and memory mimicking aspects of the patient phenotype. ASNS encodes asparagine synthetase, which catalyzes the synthesis of asparagine from glutamine and aspartate. The neurological impairment resulting from ASNS deficiency may be explained by asparagine depletion in the brain or by accumulation of aspartate/glutamate leading to enhanced excitability and neuronal damage. Our study thus indicates that asparagine synthesis is essential for the development and function of the brain but not for that of other organs.

Full Text

Duke Authors

Cited Authors

  • Ruzzo, EK; Capo-Chichi, J-M; Ben-Zeev, B; Chitayat, D; Mao, H; Pappas, AL; Hitomi, Y; Lu, Y-F; Yao, X; Hamdan, FF; Pelak, K; Reznik-Wolf, H; Bar-Joseph, I; Oz-Levi, D; Lev, D; Lerman-Sagie, T; Leshinsky-Silver, E; Anikster, Y; Ben-Asher, E; Olender, T; Colleaux, L; Décarie, J-C; Blaser, S; Banwell, B; Joshi, RB; He, X-P; Patry, L; Silver, RJ; Dobrzeniecka, S; Islam, MS; Hasnat, A; Samuels, ME; Aryal, DK; Rodriguiz, RM; Jiang, Y-H; Wetsel, WC; McNamara, JO; Rouleau, GA; Silver, DL; Lancet, D et al.

Published Date

  • October 16, 2013

Published In

Volume / Issue

  • 80 / 2

Start / End Page

  • 429 - 441

PubMed ID

  • 24139043

Electronic International Standard Serial Number (EISSN)

  • 1097-4199

Digital Object Identifier (DOI)

  • 10.1016/j.neuron.2013.08.013

Language

  • eng

Conference Location

  • United States