Confirmation of association of the GABRA2 gene with alcohol dependence by subtype-specific analysis.

Objectives: Three recent studies revealed a haplotypic association of alcohol dependence with the gene encoding the alpha2 subunit of the gamma-aminobutyric acid type A (GABAA) receptor (GABRA2). The present study examined whether variation of the GABRA2 gene confers susceptibility to different subtypes of alcohol dependence in the German population.

Methods: A total of 257 German alcohol-dependent patients and 88 healthy population controls were genotyped for six single-nucleotide polymorphisms covering the middle part and the 3' end of GABRA2.

Association analysis of malic enzyme 2 gene polymorphisms with idiopathic generalized epilepsy.

Purpose: Linkage disequilibrium mapping revealed allelic and haplotypic associations between single-nucleotide polymorphisms (SNPs) of the gene encoding the malic enzyme 2 (ME2) and adolescent-onset idiopathic generalized epilepsy (IGE). Homozygote carriers of the associated ME2 haplotype had a sixfold higher risk of IGE compared with any other genotype. The present population-based association study tested whether genetic variation of the ME2 gene confers susceptibility to common IGE syndromes in the German population.

A new EF-hand containing gene EFHC2 on Xp11.4: tentative evidence for association with juvenile myoclonic epilepsy.

Genetic factors play a major role in the etiology of idiopathic generalized epilepsies (IGE). An oligogenic or polygenic predisposition is suspected in the majority of families with common IGE syndromes. It has been hypothesized that some IGE genes might increase the general level of neuronal excitability while others specify the age of onset and the seizure type.

Association analysis of the Arg220His variation of the human gene encoding the GABA delta subunit with idiopathic generalized epilepsy.

Purpose: Mutation analysis of the gene encoding the GABA delta subunit (GABRD) identified a common missense variation (c.659G>A; Arg220His) of which the His220 allele displayed decreased GABA(A) alpha(1)beta(2)delta receptor current amplitudes. The present association study tested whether the functional GABRD His220 allele confers susceptibility to common syndromes of idiopathic generalized epilepsy (IGE).

Genetic dissection of photosensitivity and its relation to idiopathic generalized epilepsy.

Photosensitivity or photoparoxysmal response (PPR) is a common and highly heritable electroencephalographic trait characterized by an abnormal visual sensitivity of the brain in reaction to intermittent photic stimulation. PPR occurs frequently associated with idiopathic generalized epilepsies (IGEs). The present genomewide linkage scan was designed to map susceptibility loci for PPR and to explore their genetic relationship with IGE.

Association of a functional BDNF polymorphism and anxiety-related personality traits.

Rationale: Converging lines of evidence point to brain-derived neurotrophic factor (BDNF) as a factor in the pathophysiology of depression. Recently, it was shown that the Val allele of the BDNF Val66Met substitution polymorphism showed a significant association with higher mean neuroticism scores of the NEO-Five Factor Inventory (NEO-FFI) in healthy subjects, and previous studies suggested the Val allele to be increased in bipolar disorder families. The association to anxiety-related traits has not been investigated so far.