2. Academic Validation
  3. Germline and somatic mutations in the MTOR gene in focal cortical dysplasia and epilepsy

Germline and somatic mutations in the MTOR gene in focal cortical dysplasia and epilepsy

  • Neurol Genet. 2016 Oct 31;2(6):e118. doi: 10.1212/NXG.0000000000000118.
Rikke S Møller 1,  Sarah Weckhuysen 1,  Mathilde Chipaux 1,  Elise Marsan 1,  Valerie Taly 1,  E Martina Bebin 1,  Susan M Hiatt 1,  Jeremy W Prokop 1,  Kevin M Bowling 1,  Davide Mei 1,  Valerio Conti 1,  Pierre de la Grange 1,  Sarah Ferrand-Sorbets 1,  Georg Dorfmüller 1,  Virginie Lambrecq 1,  Line H G Larsen 1,  Eric Leguern 1,  Renzo Guerrini 1,  Guido Rubboli 1,  Gregory M Cooper 1,  Stéphanie Baulac 1
Affiliations

Affiliation

  • 1 The Danish Epilepsy Centre Filadelfia (R.S.M., G.R.), Dianalund, Denmark; Institute for Regional Health Services (R.S.M.), University of Southern Denmark, Odense; Sorbonne Universités (S.W., E.M., V.L., E.L., S.B.), UPMC Univ Paris 06 UMR S 1127, Inserm U1127, CNRS UMR 7225, AP-HP, Institut du cerveau et la moelle (ICM)-Hôpital Pitié-Salpêtrière, Paris, France; Epilepsy Unit (S.W., V.L.), AP-HP Groupe hospitalier Pitié-Salpêtrière, Paris, France; Neurogenetics Group (S.W.), VIB-Department of Molecular Genetics; Laboratory of Neurogenetics (S.W.), Institute Born-Bunge, University of Antwerp, Belgium; Department of Neurology (S.W.), University Hospital Antwerp, Belgium; Department of Pediatric Neurosurgery (M.C., S.F.-S., G.D.), Fondation Rothschild, Paris, France; Université Paris Sorbonne Cité (V.T.), INSERM UMR-S1147 MEPPOT, CNRS SNC5014, Centre Universitaire des Saints-Pères, Paris, France; Department of Neurology (E.M.B.), University of Alabama at Birmingham; HudsonAlpha Institute for Biotechnology (S.M.H., J.W.P., K.M.B., G.M.C.), Huntsville, AL; Pediatric Neurology, Neurogenetics and Neurobiology Unit and Laboratories (D.M., V.C., R.G.), Neuroscience Department, A Meyer Children's Hospital, University of Florence, Florence, Italy; Genosplice (P.d.l.G.), Institut du Cerveau et de la Moelle épinière, ICM, Paris, France; Amplexa Genetics (L.H.G.L.), Odense, Denmark; Department of Genetics and Cytogenetics (E.L., S.B.), AP-HP Groupe hospitalier Pitié-Salpêtrière, Paris, France; and University of Copenhagen (G.R.), Denmark.
PMID: 27830187 DOI: 10.1212/NXG.0000000000000118
Abstract

Objective: To assess the prevalence of somatic mTOR mutations in focal cortical dysplasia (FCD) and of germline mTOR mutations in a broad range of epilepsies.

Methods: We collected 20 blood-brain paired samples from patients with FCD and searched for somatic variants using deep-targeted gene panel Sequencing. Germline mutations in mTOR were assessed in a French research cohort of 93 probands with focal epilepsies and in a diagnostic Danish cohort of 245 patients with a broad range of epilepsies. Data sharing among collaborators allowed us to ascertain additional germline variants in mTOR.

Results: We detected recurrent somatic variants (p.Ser2215Phe, p.Ser2215Tyr, and p.Leu1460Pro) in the mTOR gene in 37% of participants with FCD II and showed histologic evidence for activation of the mTORC1 signaling cascade in brain tissue. We further identified 5 novel de novo germline missense mTOR variants in 6 individuals with a variable phenotype from focal, and less frequently generalized, epilepsies without brain malformations, to macrocephaly, with or without moderate intellectual disability. In addition, an inherited variant was found in a mother-daughter pair with nonlesional autosomal dominant nocturnal frontal lobe epilepsy.

Conclusions: Our data illustrate the increasingly important role of somatic mutations of the mTOR gene in FCD and germline mutations in the pathogenesis of focal epilepsy syndromes with and without brain malformation or macrocephaly.

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