Lennox-Gastaut Syndrome is a diverse syndrome with many different etiologies (causes). In about 70% - 80% of individuals who are diagnosied with LGS, the cause is understood. However, in about 20% - 30% of cases, the cause is unknown. 

 

Known Causes of LGS Include: 

 

• ​Cerebral malformations (abnormalities within child’s brain structure)

• Infections (such as meningitis)

• Hypoxic-ischemic injury 

• External trauma or injury

• Known genetic – metabolic disorders (such as tuberous sclerosis)

• Other chromosomal disorders

 

The remaining 20% - 30% of individuals with LGS have an unknown cause.  However, there has been a recent increase in research aiming to identify genes associated with Lennox-Gastaut syndrome. Numerous studies have identified new gene mutations in patients with LGS that were previously not know to be a causative factor. The Epilepsy Phenome/Genome Project and Epi4K Consortium sequenced 264 probands with either infantile spasms or Lennox-Gastaut syndrome along with their parents in an attempt to identify de novo mutations, identifying at least 2 (GABRB3 and ALG13) that had not previously been implicated[1]. Further study is needed to establish more definitive associations, causality, and hopefully inform treatment in the future. [2] 

 

Infantile Spasms precedes Lennox-Gastaut Syndome in about 30% of cases.  Those who have a history of Infantile Spasms prior to the diagnosis of LGS nearly always have a poorer prognosis with regard to intellect and epilepsy outcomes. [3]

 

 

1. Epi4K consortium. De novo mutations in epileptic encephalopathies. Nature. August 2013.  

2. Spiciarich et al.  Lennox-Gastaut Syndrome. Medmerits.com. Accessed 2.23.15.

3. Dulac and N'Guyen. The Lennox-Gastaut Syndrome. Epilepsia 1993; 34 Suppl 7