Thursday, 24 May 2012

LGI2 Gene Mutation by Andrew Synnot (42899567)


LGI2 Mutation: Possible Cause of Childhood Idiopathic Epilepsies 

by Andrew Synnot


Finnish Scientists from the University of Helsinki in Finland believe that they have discovered the mutant gene which may be responsible for the two most common human childhood epilepsy disorders – ‘Rolandic Epilepsy’ and ‘Panayiotopoulos Syndrome’. (Hannes, 2011) Through their research of Lagotto romagnolo canines, the scientists found that a mutation within the LGI2 gene causes protein truncation which results in the occurrence of a type of remittent epilepsy known as ‘Benign Familial Juvenile Epilepsy’ (BFJE)within these dogs. (Jokinen, 2007) This LGI2 gene is a homologue of the LGI1 epilepsy causing gene within humans which means that this gene could very well provide a vital link for scientists in understanding these two genetically complex disorders within humans; which have scientists perplexed over their ability to remit during adolescence. (Kalachikov, 2002)
Epilepsy is a common disorder brought on by various things such as tumours, stroke, trauma and neurodegenerative disease, however, it can occur naturally on itself (where the brain is neurologically normal except for it tendency to seize). (Roger, 2005) This type of epilepsy is known as ‘idiopathic’ epilepsy and is what classifies both Rolandic Epilepsy and Panayiotopoulos Syndrome. These two pure epilepsy syndromes most commonly affect 0.5% of children between the ages of two and ten and then suddenly show remittance during adolescence. (Roger, 2005)

Prior to the discovery of the LGI2 gene, scientist believed there was a correlation between neuronal synaptic remodelling that occurs in the brain during childhood and the presence of these idiopathic epilepsies. In all mammals, the postnatal development of the brain occurs in three phases. According to Hannes (2011, p. 3) “the first phase consists of the production of the ‘primary neural network’ (0-2 years of age in humans and 0-2 months in canines) which is constructed of around one quadrillion synapses. The next phase is known as ‘Pruning’ in which almost half the original synapses are removed by the process of selection to leave only necessary synapses and to strengthen the existing ideal connections as well as forming new links (occurs between 2-10 years in humans and approximately 2-4 months in dogs). And the third phase is then present for the remainder of mammal’s life in which the number of synapses in the brain remains stable.”