Treatment of myoclonic-atonic epilepsy caused by SLC2A1 de novo mutation with ketogenic diet: A case report

Abstract

Rationale: The SLC2A1 gene encodes glucose transporter 1 on blood-brain barrier, which plays an important role in the energy supply for neurons. Mutations in SLC2A1 gene can cause many clinical syndromes, including glucose transporter type 1 deficiency syndrome and many types of epilepsy syndromes such as childhood absence epilepsy and myoclonic-atonic epilepsy, etc. Ketogenic diet has been proved to be very effective on those cases. Clinically, SLC2A1 gene mutations are quite rare.

Patient concerns: Repeated unconsciousness and bilateral limb weakness lasted for 3 years.

Diagnoses: Myoclonic-atonic epilepsy.

Lessons: After taking whole exome sequencing, we found out that there is a de novo insertion mutation in the patient's SLC2A1 gene, leading to frameshift. As a result, ketogenic diet (2:1, 4 times a day) was used as the treatment. As for the patient, total calories intake per day was controlled at 1190 kcal. The calories per kg per day were 66.11 kcal/kg. The amount of ketone bodies was controlled at 2 to 3 mmol/L and the concentration of plasma glucose was controlled at 4 to 5 mmol/L.

Outcomes: After the launch of ketogenic diet, the patient has been seizure free for nearly a year and stopped all his antiepileptic drugs.

Conclusion: Our case suggests that gene examination is very important part of the diagnosis of epilepsy etiology and epilepsy syndromes. Ketogenic diet should be considered as the first line therapy with SLC2A1 gene mutations.

Figure 1

Clinical evaluation processes we took after receiving the patient. (A) VEEGs during wakefulness. Unsynchronized sharp and spikeslow waves appeared. (B) Sleeping VEEGs. Generalized spike and slow waves during NREM sleep appeared. VEGG = video electroencephalography.

Figure 1 (Continued)

Clinical evaluation processes we took after receiving the patient. (A) VEEGs during wakefulness. Unsynchronized sharp and spikeslow waves appeared. (B) Sleeping VEEGs. Generalized spike and slow waves during NREM sleep appeared. VEGG = video electroencephalography.

Figure 2

The first row belongs to the patient. Compared with standard sequence of SLC2A1 gene, there are a mutation in the patient's gene, a 25 bp insertion mutation between c1094 and c1095 in exom 9. There are no mutations in his parents’ exome. The red boxes indicate the insertion in the proband and normal sequences in his parents.

Figure 3

VEEGs results after ketogenic therapy for 6 months. Only few slow sharp waves appeared in his VEEGs. VEGG = video electroencephalography.