The mechanistic target of the rapamycin signaling pathway serves as a central regulator of cell metabolism, growth, proliferation, and survival. In its regulation, the GTPase-activating protein activity toward Rags1 complex has an inhibitory effect. Mutations in genes encoding this complex protein are among the most common abnormalities in focal epilepsies. Within these mutations, the mutations affecting the DEPDC5 gene have been associated with different autosomal dominantly inherited epilepsy types. Due to the limited data available on mTOR inhibitor therapy in nontuberous sclerosis complex epileptic patients, here we present the clinical management of a patient with intractable epilepsy, skin hypopigmentation, and a DEPDC5 variant. The patient's phenotype is compatible with a nonlesional DEPDC5-related epileptic encephalopathy. We initiated compassionate, off-label everolimus treatment as the patient's condition continuously deteriorated. Due to bilateral pneumonia occurring at the beginning of the treatment, it was temporarily discontinued, and resumed in half the dose. Follow-up examination after 18 months showed a 90% reduction in seizure frequency with moderate improvement in attention function and nutritional status. Our case report emphasizes the importance of early genetic testing in patients with epileptic encephalopathy. Clinical consequences of mammalian target of rapamycin complex 1 (mTORC1) upregulation may be amenable to tailored treatment with mTOR inhibitors. A clinical trial on an international scale would be needed to draw conclusions.

Received: 21 July 2022

Accepted: 18 April 2023

Accepted Manuscript online:
01 June 2023

Article published online:
30 July 2023

© 2023. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/)

Georg Thieme Verlag KG
Rüdigerstraße 14, 70469 Stuttgart, Germany