A novel de novo TET3 loss-of-function variant in a Turkish boy presenting with neurodevelopmental delay and electrical status epilepticus during slow-wave sleep

Beck-Fahrner syndrome is caused by homozygous or heterozygous mutations in TET3 on chromosome 2p13. The general characteristics of this syndrome include behavioral abnormalities such as autistic features, attention-deficit hyperactivity disorder, learning disabilities, and epilepsy. Six years old ma...

Full description

Saved in:
Bibliographic Details
Published inBrain & development (Tokyo. 1979) Vol. 45; no. 2; pp. 140 - 145
Main Authors Sager, Safiye Gunes, Turkyilmaz, Ayberk, Gunbey, Hediye Pınar, Karatoprak, Elif Yuksel, Aslan, Elif Sibel, Akın, Yasemin
Format Journal Article
LanguageEnglish
Published Netherlands Elsevier B.V 01.02.2023
Subjects
Child
Clobazam - therapeutic use
Dioxygenases
Electrical status epilepticus during slow-wave sleep
Electroencephalography
Epilepsy
Humans
Infant
Male
Sleep
Sleep, Slow-Wave
Status epilepticus
Status Epilepticus - drug therapy
TET3 gene
Treatment
Valproic Acid - therapeutic use
Treatment
Electrical status epilepticus during slow-wave sleep
Status epilepticus
Epilepsy
TET3 gene
Online AccessGet full text

Cover

More Information
Summary:Beck-Fahrner syndrome is caused by homozygous or heterozygous mutations in TET3 on chromosome 2p13. The general characteristics of this syndrome include behavioral abnormalities such as autistic features, attention-deficit hyperactivity disorder, learning disabilities, and epilepsy. Six years old male patient was found to have a de novo TET3 loss-of-function variant by whole-exome sequencing (WES) analysis and was diagnosed with electrical status epilepticus during slow-wave sleep (ESES) based on clinical and electroencephalogram (EEG) characteristics. The patient had a neurodevelopmental delay from the age of 3 months and started experiencing generalized tonic–clonic seizures and regression at the age of 5 years. EEG findings were consistent with ESES, and WES analysis revealed a novel heterozygous nonsense NM_001366022.1:c.1594C > T (p.Arg532*) variant in TET3. Valproic acid and immunotherapy were administered for the first 6 months, and clobazam was administered orally in addition to oral valproic acid therapy for the next 6 months. Clinical improvement was noted regardless of EEG improvement for the first 6 months. EEG improvement was achieved with clobazam. No regression was observed following the discontinuation of immunotherapy. Decreased TET3 enzyme activity may be one of the new genetic etiologies of ESES.
ISSN:0387-7604
1872-7131
DOI:10.1016/j.braindev.2022.09.004