In up to one-third of cases no cause can be found. Brain injury
Lennox–Gastaut most often occurs secondary to brain damage. The brain damage can occur from perinatal insults, encephalitis, meningitis, tumor, and brain malformation. Genetic mutations
Other identified disorders include genetic disorders such as tuberous sclerosis and inherited deficiency of methylene tetrahydrofolate reductase. Some of these cases once thought to be of unknown cause may have definitive etiology by modern genetic testing.Progress in genome and exome sequencing is revealing that some individuals diagnosed with Lennox-Gastaut Syndrome have de novo mutations in a variety of genes, including CHD2, GABRB3, ALG13 and SCN2A. The Epi4K study consortium (2013) observed de novo mutations in at least 15% of a study cohort of 165 patients with LGS and infantile spasms using whole exome sequencing. A 2013 study found a high frequency of rare copy-number variation (CNVs) in adult patients with LGS or LGS-like epilepsy.Mutations in the IQSEC2 gene have been associated with this syndrome. This gene is located on the short arm of the X chromosome (Xp11.22). Diagnosis
The diagnosis of LGS should be suspected in children less than 8 years old with seizures of multiple types that cannot be treated with antiseizure medications. Because of high risk of irreversible brain damage in early stages of syndrome (particularly in infants and young children), early diagnosis is essential.
Pulmonary vein stenosis is a rare cardiovascular disorder. It is recognized as being the stenosis of one or more of the four pulmonary veins that return blood from the lungs to the left atrium of the heart. In congenital cases, it is associated with poor prognosis and high mortality rate. In some people, pulmonary vein stenosis occurs after pulmonary vein ablation for the treatment of atrial fibrillation. Some recent research has indicated that it may be genetically linked in congenital cases. == References ==