0000000000672604
AUTHOR
Xiaohui Xu
Association of ADHD with genetic variants in the 5'-region of the dopamine transporter gene: evidence for allelic heterogeneity.
Contains fulltext : 69953.pdf (Publisher’s version ) (Closed access) Multiple studies have reported an association between attention deficit hyperactivity disorder (ADHD) and the 10-repeat allele of a variable number tandem repeat (VNTR) polymorphism in the 3'-untranslated region (3'UTR) of the dopamine transporter gene (DAT1). Yet, recent meta-analyses of available data find little or no evidence for this association; although there is strong evidence for heterogeneity between datasets. This pattern of findings could arise for several reasons including the presence of relatively rare risk alleles on common haplotype backgrounds or the functional interaction of two or more loci within the g…
A high-density SNP linkage scan with 142 combined subtype ADHD sib pairs identifies linkage regions on chromosomes 9 and 16
As part of the International Multi-centre ADHD Gene (IMAGE) project we have completed an affected sibling pair study of 142 narrowly defined DSM-IV combined type ADHD proband-sibling pairs. We found suggestive linkage on chromosomes 9 and 16 with non-parametric multipoint peak LOD scores of 2.13 and 3.1 respectively. There have been several previous ADHD linkage scans. The UCLA study (Fisher et al. 2002; Ogdie et al. 2004; Ogdie et al. 2003), the Dutch study (Bakker et al. 2003), the German study (Hebebrand et al. 2006) and the MGH Study (Faraone et al., submitted) applied the affected sib pair (ASP) strategy; the Columbian study used extended pedigrees ascertained from a population isolate…
Linkage to chromosome 1p36 for attention-deficit/hyperactivity disorder traits in school and home settings.
Contains fulltext : 69485.pdf (Publisher’s version ) (Closed access) BACKGROUND: Limited success has been achieved through previous attention-deficit/hyperactivity disorder (ADHD) linkage scans, which were all designed to map genes underlying the dichotomous phenotype. The International Multi-centre ADHD Genetics (IMAGE) project performed a whole genome linkage scan specifically designed to map ADHD quantitative trait loci (QTL). METHODS: A set of 1094 single selected Caucasian ADHD nuclear families was genotyped on a highly accurate and informative single nucleotide polymorphism (SNP) panel. Two quantitative traits measuring the children's symptoms in home and school settings were collecte…
Genetic heterogeneity in ADHD: DAT1 gene only affects probands without CD
Contains fulltext : 70183.pdf (Publisher’s version ) (Closed access) Previous studies have found heterogeneous association between DAT1-3'-UTR-VNTR and attention deficit hyperactivity disorder (ADHD). Various proportions of conduct disorder (CD) comorbidity in their ADHD samples may partially explain the observational discrepancies. Evidence for this comes from family and twin studies which found ADHD probands with CD (ADHD + CD) are genetically different from those without CD (ADHD - CD). Genotypes of 20 DAT1 markers were analyzed in 576 trios, consisting of 141 ADHD + CD and 435 ADHD - CD. In addition to the classical TDT test, a specific genetic heterogeneity test was performed to identi…