Family, twin, and adoption studies have indicated that human intelligence quotient (IQ) has significant genetic components. We performed a low-density genome-wide association analysis with a family-based association test to identify genetic variants influencing IQ, as measured by Wechsler Adult Intelligence Scale full-score IQ (FSIQ). We examined 11,120 single-nucleotide polymorphisms (SNPs) from the Affymetrix GeneChips 10K mapping array genotyped in 292 nuclear families from Genetic Analysis Workshop 14, a subset from the Collaborative Study on the Genetics of Alcoholism (COGA). A replication analysis was performed using part of International Multi-Center ADHD Genetics Project (IMAGE) dataset. Twenty-two SNPs were identified as having suggestive associations with IQ (p<10(-3)) in the COGA sample and eleven of the SNPs were located within known genes. In particular, NTM at 11q25 (rs411280, p = 0.000764) and NR3C2 at 4q31.1 (rs3846329, p = 0.000675) were two novel genes which have not been associated with IQ in other studies. It has been reported that NTM might play a role in late-onset Alzheimer disease while NR3C2 may be associated with cognitive function and major depression. The associations of these two genes were well-replicated by single-marker and haplotype analyses in the IMAGE sample. In conclusion, our findings provide evidence that chromosome regions of 11q25 and 4q31.1 contain genes affecting IQ. This study will serve as a resource for replication in other populations.
"treatment ( Garson , 2013 ; Ma et al . , 2012 ) . The autoregressive covariance structure was selected because the correlations between CSSA evaluations ( at times 1e4 ) declined with time . The IQ and skin color were tested as potential confounders . IQ was included since there are studies showing as - sociations of NR3C2 SNPs with intelligence ( Pan et al . , 2011 ; van der Voorn et al . , 2015 ) . As recommended in the literature , a variable is considered a confounder when it is associated with both variables of interest ( association with both the outcome and studied SNPs for a P - value < 0 . 2 ) ( Cordell , 2009 ; Maldonado and Greenland , 1993 ) ."
"These include variants in the CHRM2, COMT and BDNF genes . GWASs, which have recently had an enormous success in identifying genetic variants contributing to complex traits, had little success in mapping variants associated with cognitive abilities, with no indication of major genetic contributing loci , , . The generally accepted model proposes that cognitive abilities are influenced by many genes of small effect  and are therefore difficult to map in the relatively small-sized samples currently available. "
[Show abstract][Hide abstract] ABSTRACT: Independent studies have shown that candidate genes for dyslexia and specific language impairment (SLI) impact upon reading/language-specific traits in the general population. To further explore the effect of disorder-associated genes on cognitive functions, we investigated whether they play a role in broader cognitive traits. We tested a panel of dyslexia and SLI genetic risk factors for association with two measures of general cognitive abilities, or IQ, (verbal and non-verbal) in the Avon Longitudinal Study of Parents and Children (ALSPAC) cohort (N>5,000). Only the MRPL19/C2ORF3 locus showed statistically significant association (minimum P = 0.00009) which was further supported by independent replications following analysis in four other cohorts. In addition, a fifth independent sample showed association between the MRPL19/C2ORF3 locus and white matter structure in the posterior part of the corpus callosum and cingulum, connecting large parts of the cortex in the parietal, occipital and temporal lobes. These findings suggest that this locus, originally identified as being associated with dyslexia, is likely to harbour genetic variants associated with general cognitive abilities by influencing white matter structure in localised neuronal regions.
PLoS ONE 11/2012; 7(11):e50321. DOI:10.1371/journal.pone.0050321 · 3.23 Impact Factor
"Likewise, another new direct and functional target of miR-182, NTM, was also identified. NTM is a member of the family of neural cell adhesion molecules (NCAM) (34), mediates cell–cell recognition and helps to promote axonal fasciculation, to guide nerve fibers towards specific targets and to stabilize synapses during nerve development (35,36). NCAM is involved in cell growth, migration and differentiation, especially the ectopic expression of polysialylated NCAM promotes adult macaque SC migration and improves their integration among astrocytes in vitro without modifying their antigenic properties as either non-myelinating or pro-myelinating (37). "
[Show abstract][Hide abstract] ABSTRACT: The regulation of Schwann cell (SC) responses to injury stimuli by microRNAs (miRNAs) remains to be explored. Here, we identified 17 miRNAs that showed dynamic expression alterations at five early time points following rat sciatic nerve resection. Then we analyzed the expression pattern of 17 miRNAs, and integrated their putative targets with differentially expressed mRNAs. The resulting 222 potential targets were mainly involved in cell phenotype modulation, including immune response, cell death and cell locomotion. Among 17 miRNAs, miR-182 expression was up-regulated. The enhanced expression of miR-182 was correlated with nerve injury-induced phenotype modulation of SCs. Further investigation revealed that fibroblast growth factor 9 (FGF9) and neurotrimin (NTM) were two direct targets of miR-182 in SCs, with miR-182 binding to the 3'-untranslated region of FGF9 and NTM. Silencing of FGF9 and NTM recapitulated the inhibiting effect of miR-182 mimics on SC proliferation and migration, respectively, whereas enforced knockdown of FGF9 and NTM reversed the promoting effect of miR-182 inhibitor on SC proliferation and migration, respectively. Our data indicate that nerve injury inhibits SC proliferation and migration through rapid regulation of miR-182 by targeting FGF9 and NTM, providing novel insights into the roles of miRNAs in nerve injury and repair.
Nucleic Acids Research 08/2012; 40(20). DOI:10.1093/nar/gks750 · 9.11 Impact Factor
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.