Genetic association of the EGR2 gene with bipolar disorder in Korea

The early growth response gene 2 (EGR2) is located at chromosome 10q21, one of the susceptibility loci in bipolar disorder (BD). EGR2 is involved in cognitive function, myelination, and signal transduction related to neuregulin-ErbB receptor, Bcl-2 family proteins, and brain-derived neurotrophic factor. This study investigated the genetic association of the EGR2 gene with BD and schizophrenia (SPR) in Korea. In 946 subjects (350 healthy controls, 352 patients with BD, and 244 with SPR), nine single nucleotide polymorphisms (SNPs) in the EGR2 gene region were genotyped. Five SNPs showed nominally significant allelic associations with BD (rs2295814, rs61865882, rs10995315, rs2297488, and rs2297489), and the positive associations of all except rs2297488 remained significant after multiple testing correction. Linkage disequilibrium structure analysis revealed two haplotype blocks. Among the common identified haplotypes (frequency > 5%), 'T-G-A-C-T (block 1)' and 'A-A-G-C (block 2)' haplotypes were over-represented, while 'C-G-G-T-T (block 1)' haplotype was under-represented in BD. In contrast, no significant associations were found with SPR. Although an extended analysis with a larger sample size or independent replication is required, these findings suggest a genetic association of EGR2 with BD. Combined with a plausible biological function of EGR2, the EGR2 gene is a possible susceptibility gene in BD.

Gene Expression Profiles in Genetically Different Mice Infected with Toxoplasma gondii: ALDH1A2, BEX2, EGR2, CCL3 and PLAU

Toxoplasma gondii can modulate host cell gene expression; however, determining gene expression levels in intermediate hosts after T. gondii infection is not known much. We selected 5 genes (ALDH1A2, BEX2, CCL3, EGR2 and PLAU) and compared the mRNA expression levels in the spleen, liver, lung and small intestine of genetically different mice infected with T. gondii. ALDH1A2 mRNA expressions of both mouse strains were markedly increased at day 1-4 postinfection (PI) and then decreased, and its expressions in the spleen and lung were significantly higher in C57BL/6 mice than those of BALB/c mice. BEX2 and CCR3 mRNA expressions of both mouse strains were significantly increased from day 7 PI and peaked at day 15-30 PI (P<0.05), especially high in the spleen liver or small intestine of C57BL/6 mice. EGR2 and PLAU mRNA expressions of both mouse strains were significantly increased after infection, especially high in the spleen and liver. However, their expression patterns were varied depending on the tissue and mouse strain. Taken together, T. gondii-susceptible C57BL/6 mice expressed higher levels of these 5 genes than did T. gondii-resistant BALB/c mice, particularly in the spleen and liver. And ALDH1A2 and PLAU expressions were increased acutely, whereas BEX2, CCL3 and EGR2 expressions were increased lately. Thus, these demonstrate that host genetic factors exert a strong impact on the expression of these 5 genes and their expression patterns were varied depending on the gene or tissue.

Molecular Genetics of Autosomal-Recessive Demyelinating Charcotmarie-Tooth Disease (Review Article) / Монголын Анагаах Ухаан

Charcot-Marie-Tooth disease (CMT) is a clinically and genetically heterogenous group of disorders. Useful classifi cation is still clinical and electrophysiological classifi cation that divides CMT into CMT type 1 - demyelinating form and CMT type 2 - axonal form. An intermediate type is also increasingly being determined. Inheritance can be autosomal dominant, X-linked and autosomal recessive (AR). In this review, we will focus on the clinical and/or electrophysiological findings and molecular genetics of ARCMT1 (CMT4). Ten genes, GDAP1, MTMR2, MTMR13, SH3TC2, NDRG1, EGR2, PRX, CTDP1, FGD4 and SAC3 have been identifi ed in the CMT4A, CMT4B1, CMT4B2, CMT4C, CMT4D, CMT4E, CMT4F, CCFDN, CMT4H and CMT4J types, respectively. In addition, susceptibility locus on chromosome 10q23 has been found for CMT4G disease. Molecular genetics of demyelinating ARCMT are large disabilities of proteins in Schwann cells and their functions (transcriptional factor, protein transport, protein sorting, intra/extra cellular compartments, signal transduction, cell division, and cell differentiation). It has been rising necessary requirements to defi ne clinical and genetic subtypes of the ARCMT1, prevent from disease, give reproductive and genetic counselling, and develop methods for reducing and clear disease risk factor.

A Novel V136A Mutation in Cx32 and a R359W Mutation in EGR2 within a Charcot-Marie-Tooth Patient

Mutations of the CMT genes develop a variety of distinct phenotypes. Cx32 gene mutations cause the X-linked form of CMT disease, and mutations in EGR2 are associated with CMT type 1, DSS, and congenital hypomyelination neuropathy. Her parents, grandmother and sister did not show the V136A mutation in Cx32. We report the first CMT patient with EGR2 and Cx32 mutations.