# Tuberous Sclerosis Due to Deletion of Exons 4–8 in TSC2 Gene, Favourably Responding to Phenytoin and Everolimus: A Case Report

## TL;DR

A 24-year-old woman with tuberous sclerosis due to a rare TSC2 gene mutation showed significant improvement with phenytoin for epilepsy and everolimus for tumor regression.

## Contribution

This is the first reported case of TSC with a TSC2 exon 4–8 deletion responding well to phenytoin and everolimus.

## Key findings

- Phenytoin effectively controlled seizures in a TSC patient with a rare TSC2 mutation.
- Everolimus led to significant regression of multi-organ hamartomas in the patient.
- The case challenges the assumption that TSC-related epilepsy is intractable.

## Abstract

A case of tuberous sclerosis (TSC) caused by a previously unreported mutation, with epilepsy responding well to phenytoin (PHT) and multilocular benign tumors regressing with everolimus, has not been documented before, to the best of our knowledge. The patient is a 24-year-old female who was diagnosed with tuberous sclerosis complex (TSC) at the age of seven due to epilepsy and the presence of multiple hamartomas, including angiofibromas, angiomyolipomas, lymphangioleiomyomas, rhabdomyomas, and astrocytomas, throughout her body. She also has a history of developmental delay, mild cognitive impairment, adjustment disorder, claustrophobia, recurrent depressive episodes, anxiety disorder, and autism spectrum disorder. Genetic testing confirmed a deletion of exons 4-8 in the TSC2 gene. At the age of 10, monotherapy with PHT was started, which had such a favorable effect that no more seizures occurred until the age of 19. From the age of 19, she also received everolimus, as a result of which the multi-organ hamartomas regressed significantly. This case shows that epilepsy in TSC is not intractable, that phenytoin could be an option for epilepsy in TSC patients, and that everolimus is very effective in terms of regression of benign tumors.