LGI1 microdeletion in autosomal dominant lateral temporal epilepsy

Area of Science:

• Genetics
• Neurology
• Epilepsy

Background:

• Autosomal dominant lateral temporal epilepsy (ADLTE) is a rare genetic epilepsy.
• LGI1 gene mutations are a known cause of ADLTE.
• Standard LGI1 exon sequencing can miss certain genetic alterations.

Purpose of the Study:

• To investigate the genetic cause of ADLTE in a family negative for LGI1 point mutations.
• To characterize the clinical and genetic features of the affected family.
• To identify novel genetic mechanisms underlying ADLTE.

Main Methods:

• Clinical interviews and neurological examinations of family members.
• Electroencephalography (EEG) and neuroimaging (CT/MRI) in affected individuals.
• High-density single nucleotide polymorphism (SNP) array for copy number variation (CNV) analysis and quantitative PCR (qPCR) for gene dosage.

Main Results:

• A family with three generations affected by ADLTE was studied.
• All affected members exhibited generalized tonic-clonic (GTC) seizures, with focal onset in most.
• A significant microdeletion encompassing the first four exons of the LGI1 gene was identified in affected individuals using CNV analysis.

Conclusions:

• This study reports the first identified LGI1 microdeletion in ADLTE.
• CNV analysis should be considered for ADLTE families negative for point mutations.
• Microdeletion detection through CNV analysis can uncover novel disease-causing genes.