Showing papers by "Ke Xu published in 2007"

Gender-specific effects of the catechol-O-methyltransferase Val108/158Met polymorphism on cognitive function in children.

Abstract: Objective: The study aimed to determine the cognitive effect of the Val 108/158 Met polymorphism in the catechol- O -methyltransferase (COMT) gene in children before and during puberty. This polymorphism affects cognitive function in healthy adults and may contribute to risk for schizophrenia. Method: COMT genotype was determined for 8,707 children from the Avon Longitudinal Study of Parents and Children (ALSPAC), a geographically defined general population cohort of children born between April 1, 1991, and Dec. 31, 1992, in the southwest of England. Fourteen measures of cognitive function—including working memory, verbal and motor inhibition, attentional control, and IQ—were assessed at ages 8 and 10 years. Any pubertal development at age 9 years was reported by parents. Effects of COMT genotype on cognition and interactions with gender and puberty were assessed using general linear models. Results: In boys, genotype significantly affected executive function and explained up to 10 points normal variation...

Nucleotide sequence variation within the human tyrosine kinase B neurotrophin receptor gene: association with antisocial alcohol dependence.

Abstract: To identify sequence variants in genes that may have roles in neuronal responses to alcohol, we resequenced the 5′ region of NTRK2 and determined linkage disequilibrium (LD) values, haplotype structure, and performed association analyses using 43 single nucleotide polymorphisms (SNPs) covering the entire NTRK2 region in a Finnish Caucasian sample of 229 alcohol dependent subjects with antisocial personality disorder and 287 healthy controls. Individually, three SNPs were associated with alcohol dependence and alcohol abuse (AD)(P-value from 0.0019 to 0.0059, significance level was set at P ≤ 0.01 corrected for multiple testing), while a common eighteen-locus haplotype within the largest LD block of NTRK2, a 119 kb region containing the 5′ flanking region and exons 1 through 15, was marginally overrepresented in control subjects compared to AD individuals (global P = 0.057). Taken together, these results support a role for the NTRK2 gene in addiction in a Caucasian population with AD and a subtype of antisocial personality disorder.

Irritable assault and variation in the COMT gene.

Abstract: Aggression is associated with the 'low' activity allele (Met) of the functional Val158Met polymorphism among people with schizophrenia spectrum disorders relative to the 'high' activity (Val) allele. We examined this polymorphism in a sample of 112 people with axis II personality disorders. Participants completed the Buss Durkee Hostility Inventory. Two single nucleotide polymorphisms in the COMT gene were genotyped in these participants classified as 'white' according to US Census Bureau definitions. We failed to observe an association between the Val158Met allele and aggression but observed an association between self-reported aggression and the G allele of a biallelic polymorphism located in the 3'' UTR (rs16559). This allele is less prevalent among schizophrenics and is associated with lower COMT expression in the brain. These findings provide limited support for a role of COMT in modulating aggressive behavior, and are extended to people with personality disorders. Language: en