Fiche publication
Date publication
août 2020
Journal
European journal of medical genetics
Auteurs
Membres identifiés du Cancéropôle Est :
Pr BARDOU Marc
,
Pr HUET Frédéric
,
Pr FAIVRE Laurence
,
Pr VABRES Pierre
,
Pr THAUVIN-ROBINET Christel
Tous les auteurs :
Hadouiri N, Darmency V, Guibaud L, Arzimanoglou A, Sorlin A, Carmignac V, Rivière JB, Huet F, Luu M, Bardou M, Thauvin-Robinet C, Vabres P, Faivre L
Lien Pubmed
Résumé
The MTOR gene encodes the mechanistic target of rapamycin (mTOR), which is a core component of the PI3K-AKT-mTOR signaling pathway. Postzygotic MTOR variants result in various mosaic phenotypes, referred to in OMIM as Smith-Kinsgmore syndrome or focal cortical dysplasia. We report here the case of a patient, with an MTOR mosaic gain-of-function variant (p.Glu2419Lys) in the DNA of 41% skin cells, who received compassionate off-label treatment with everolimus for refractory epilepsy. This 12-year-old-girl presented with psychomotor regression, intractable seizures, hypopigmentation along Blaschko's lines (hypomelanosis of Ito), asymmetric regional body overgrowth, and ocular anomalies, as well as left cerebral hemispheric hypertrophy with some focal underlying migration disorders. In response to the patient's increasingly frequent epileptic seizures, everolimus was initiated (after approval from the hospital ethics committee) at 5 mg/day and progressively increased to 12.5 mg/day. After 5 months of close monitoring (including neuropsychological and electroencephalographic assessment), no decrease in seizure frequency was observed. Though the physiopathological rationale was good, no significant clinical response was noticed under everolimus treatment. A clinical trial would be needed to draw conclusions, but, because the phenotype is extremely rare, it would certainly need to be conducted on an international scale.
Mots clés
Everolimus, Mosaic mTOR mutation, Seizures, Therapy in rare diseases, mTOR
Référence
Eur J Med Genet. 2020 Aug 14;:104036
