Maniyar Roshan Z1, M. A. Doshi2, B. N. Umarji3, Praveen Jahan4, Parthasaradhi5, G. Shivannarayana6, Aravind Kumar7, H. Shashikanth8
ABSTRACT: Juvenile Myoclonic Epilepsy (JME) or Janz syndrome is inherited disorder, otherwise neurologically normal.(1) The prevalence of JME is estimated around 3 in 10, 000. The genetic mutations in JME patients affecting non-ion channels and the exact mode of JME inheritance are not clear. Mutation within an exon of a structural gene can alter the functioning of the gene product and cause a dramatic phenotypic change. METHOD: The case-control association study design was used to test the potential involvement of LGI4 gene variations in the etiology of JME. We analyzed mutation for molecular screening of LGI4 sequence coding 2-3 exon. Detection of mutation was performed by genomic PCR amplification and direct sequencing by ABI PRISM® 377 DNA Analyzer. RESULT: We identified novel mutation (36%) in LGI4 gene changes G-to-N transversion at base pair 112 polymorphic site in exon 2-3. The novel mutation can change to the alteration of a chromosomal loci on 19q 13.11. The LGI4 gene secreted glycosylated leucine-rich repeat protein that involved in Schwann cells for the formation of myelin sheath. Demyelination of sheath may damage the axon which leads to JME. CONCLUSION: The exact mechanism of JME involved different gene mutations is still unknown. Further Familial and twin studies are required to investigate the strong involvement of LGI1, LGI2 and LGI4 genes in the genetic susceptibility of JME syndrome for the role of CNS and PNS.
