TY - JOUR
T1 - Mutations in SYNGAP1 Cause Intellectual Disability, Autism, and a Specific Form of Epilepsy by Inducing Haploinsufficiency
AU - Berryer, Martin H
AU - Hamdan, Fadi F
AU - Klitten, Laura L
AU - Møller, Rikke S
AU - Carmant, Lionel
AU - Schwartzentruber, Jeremy
AU - Patry, Lysanne
AU - Dobrzeniecka, Sylvia
AU - Rochefort, Daniel
AU - Neugnot-Cerioli, Mathilde
AU - Lacaille, Jean-Claude
AU - Niu, Zhiyv
AU - Eng, Christine M
AU - Yang, Yaping
AU - Palardy, Sylvain
AU - Belhumeur, Céline
AU - Rouleau, Guy A
AU - Tommerup, Niels
AU - Immken, Ladonna
AU - Beauchamp, Miriam H
AU - Patel, Gayle Simpson
AU - Majewski, Jacek
AU - Tarnopolsky, Mark A
AU - Scheffzek, Klaus
AU - Hjalgrim, Helle
AU - Michaud, Jacques L
AU - Di Cristo, Graziella
N1 - © 2012 WILEY PERIODICALS, INC.
PY - 2013/2
Y1 - 2013/2
N2 - De novo mutations in SYNGAP1, which codes for a RAS/RAP GTP-activating protein, cause nonsyndromic intellectual disability (NSID). All disease-causing point mutations identified until now in SYNGAP1 are truncating, raising the possibility of an association between this type of mutations and NSID. Here, we report the identification of the first pathogenic missense mutations (c.1084T>C [p.W362R], c.1685C>T [p.P562L]) and three novel truncating mutations (c.283dupC [p.H95PfsX5], c.2212_2213del [p.S738X], and (c.2184del [p.N729TfsX31]) in SYNGAP1 in patients with NSID. A subset of these patients also showed ataxia, autism, and a specific form of generalized epilepsy that can be refractory to treatment. All of these mutations occurred de novo, except c.283dupC, which was inherited from a father who is a mosaic. Biolistic transfection of wild-type SYNGAP1 in pyramidal cells from cortical organotypic cultures significantly reduced activity-dependent phosphorylated extracellular signal-regulated kinase (pERK) levels. In contrast, constructs expressing p.W362R, p.P562L, or the previously described p.R579X had no significant effect on pERK levels. These experiments suggest that the de novo missense mutations, p.R579X, and possibly all the other truncating mutations in SYNGAP1 result in a loss of its function. Moreover, our study confirms the involvement of SYNGAP1 in autism while providing novel insight into the epileptic manifestations associated with its disruption.
AB - De novo mutations in SYNGAP1, which codes for a RAS/RAP GTP-activating protein, cause nonsyndromic intellectual disability (NSID). All disease-causing point mutations identified until now in SYNGAP1 are truncating, raising the possibility of an association between this type of mutations and NSID. Here, we report the identification of the first pathogenic missense mutations (c.1084T>C [p.W362R], c.1685C>T [p.P562L]) and three novel truncating mutations (c.283dupC [p.H95PfsX5], c.2212_2213del [p.S738X], and (c.2184del [p.N729TfsX31]) in SYNGAP1 in patients with NSID. A subset of these patients also showed ataxia, autism, and a specific form of generalized epilepsy that can be refractory to treatment. All of these mutations occurred de novo, except c.283dupC, which was inherited from a father who is a mosaic. Biolistic transfection of wild-type SYNGAP1 in pyramidal cells from cortical organotypic cultures significantly reduced activity-dependent phosphorylated extracellular signal-regulated kinase (pERK) levels. In contrast, constructs expressing p.W362R, p.P562L, or the previously described p.R579X had no significant effect on pERK levels. These experiments suggest that the de novo missense mutations, p.R579X, and possibly all the other truncating mutations in SYNGAP1 result in a loss of its function. Moreover, our study confirms the involvement of SYNGAP1 in autism while providing novel insight into the epileptic manifestations associated with its disruption.
U2 - 10.1002/humu.22248
DO - 10.1002/humu.22248
M3 - Journal article
C2 - 23161826
SN - 1059-7794
VL - 34
SP - 385
EP - 394
JO - Human Mutation
JF - Human Mutation
IS - 2
ER -