Figures & data
TABLE 1. Neurobehavioral Tests Assessed With Mean Scores for Year 7 (Final Year of Clinical Trial)
TABLE 2. Study Population Characteristics for Participants at Entry (Baseline) and in Year 2 and Year 7
TABLE 3. Acute Hg Dose-Response Effects in Year 2 Among Boys and Girls by WT or Mut Allelic Status for COMT SNPs
TABLE 4. Distribution of Three COMT Variants Among Boys
TABLE 5. Chronic Hg Dose-Response Effects in Year 7 Among Boys and Girls by WT or Mut Allelic Status for COMT SNPs
TABLE 6. Acute Hg Dose-Response Effects Among Boys and Girls With ACGG (Group A) or GTCA (Group B) COMT haplotype
TABLE 7. Chronic Hg Dose-Response Effects Among Boys and Girls With ACGG (Group A) or GTCA (Group B) COMT Haplotype
FIGURE 1. Haplotype block structure of the COMT gene in study subjects. Linkage disequilibrium (LD) plot statistics of rs6269, rs4633, rs4818, and 4680. L1 = Locus 1; L2 = Locus 2; D′ = D prime, a measure of pairwise LD; LOD (logarithm of odds) = LOD score; r 2 = goodness of fit. Haplotype block structure is as depicted by Haploview. Values for D′ (×100) are shown in shaded cells; cells with D′ = 1.00 are shaded without values indicated.
FIGURE 2. Associations between performance on the Rey Auditory Verbal Learning Test (RAVLT) Trials 1–5: Sum of Learning & Memory and acute Hg exposure among boys. Scatter plots and simple linear regression fit lines of RAVLT Trials 1–5: Sum test scores by acute Hg exposure (ln[HgU + 1]) are plotted to distinguish boys with the COMT Group B haplotype Mut (ATCAmet-ATCAmet) (open circles, solid line) versus those with Not Group B haplotype status (closed circles, dashed line). The linear slope r 2 values for Group B and Not Group B are .126 and 2.562E-4, respectively (p < .02). Thus, while acute Hg exposure explains 12.6% of the performance variation among boys with the Group B haplotype, Hg explains virtually no variation among those with Not Group B status.
![FIGURE 2. Associations between performance on the Rey Auditory Verbal Learning Test (RAVLT) Trials 1–5: Sum of Learning & Memory and acute Hg exposure among boys. Scatter plots and simple linear regression fit lines of RAVLT Trials 1–5: Sum test scores by acute Hg exposure (ln[HgU + 1]) are plotted to distinguish boys with the COMT Group B haplotype Mut (ATCAmet-ATCAmet) (open circles, solid line) versus those with Not Group B haplotype status (closed circles, dashed line). The linear slope r 2 values for Group B and Not Group B are .126 and 2.562E-4, respectively (p < .02). Thus, while acute Hg exposure explains 12.6% of the performance variation among boys with the Group B haplotype, Hg explains virtually no variation among those with Not Group B status.](/cms/asset/909e6c27-d9e5-416f-b332-481a8cd42fcd/uteh_a_867210_o_f0002g.gif)
FIGURE 3. Associations between performance on the WAIS-III Digit Symbol test of Visual-Spatial acuity and chronic cumulative Hg exposure among boys. Scatter plots and simple linear regression fit lines of WAIS-III Digit Symbol test scores by chronic cumulative Hg exposure (ln[(∑HgU) + 1]) are plotted to distinguish boys with the COMT Group B haplotype Mut (ATCAmet-ATCAmet) (open circles, solid line) versus those with Not Group B haplotype status (closed circles, dashed line). Linear slope r 2 values for Group B and Not Group B are .270 and .007, respectively (p < .006). Thus, while chronic Hg exposure explains 27% of the performance variation among boys with the Group B haplotype, it explains less than 1% of variation among those with Not Group B status.
![FIGURE 3. Associations between performance on the WAIS-III Digit Symbol test of Visual-Spatial acuity and chronic cumulative Hg exposure among boys. Scatter plots and simple linear regression fit lines of WAIS-III Digit Symbol test scores by chronic cumulative Hg exposure (ln[(∑HgU) + 1]) are plotted to distinguish boys with the COMT Group B haplotype Mut (ATCAmet-ATCAmet) (open circles, solid line) versus those with Not Group B haplotype status (closed circles, dashed line). Linear slope r 2 values for Group B and Not Group B are .270 and .007, respectively (p < .006). Thus, while chronic Hg exposure explains 27% of the performance variation among boys with the Group B haplotype, it explains less than 1% of variation among those with Not Group B status.](/cms/asset/fd3979b0-1787-4e6a-96d7-291ecaf1de5b/uteh_a_867210_o_f0003g.gif)