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Biomedical subjects

Carolien Panhuysen

Publications and source records attributed to Carolien Panhuysen.

7 recordsLinked to original sources

Haplotype spanning TTC12 and ANKK1, flanked by the DRD2 and NCAM1 loci, is strongly associated to nicotine dependence in two distinct American populations.

Nicotine dependence (ND) is a moderately heritable trait. We ascertained a set of 1615 subjects in 632 families [319 African-American (AA) and 313 European-American (EA)] based on affected sibling pairs with cocaine or opioid dependence. Subjects were interviewed with the Semi-Structured Assessment for Drug Dependence and Alcoholism (SSADDA). Previously, we identified a modest linkage peak (LOD score =1.97) for ND in the EA part of the sample on chromosome 11q23, a region that includes the NCAM1-TTC12-ANKK1-DRD2 gene cluster. DRD2 and NCAM1 are functional candidate genes for substance dependence; the TTC12 and ANKK1 loci are not well characterized. We genotyped a set of 43 single nucleotide polymorphisms (SNPs) spanning this region, and performed family-based association and haplotype analysis. There was relatively weak evidence for association of the flanking DRD2 and NCAM1 markers to ND, but very strong evidence of association of multiple SNPs at TTC12 and ANKK1 in both populations (minimal P=0.0007 in AAs and minimal P=0.00009 in EAs), and in the pooled sample, as well as strong evidence for highly significant association of a single haplotype spanning TTC12 and ANKK1 to ND in the pooled sample (P=0.0000001). We conclude that a risk locus for ND, important both in AAs and EAs, maps to a region that spans TTC12 and ANKK1. Functional studies of these loci are warranted. These results provide additional information useful in evaluating the many earlier discrepant findings regarding association of DRD2 with substance dependence.

Adult↗

Genomewide linkage scan for nicotine dependence: identification of a chromosome 5 risk locus.

BACKGROUND: Nicotine dependence (ND) is costly to societies worldwide, moderately heritable, and genetically complex. Risk loci can be identified with genetic linkage analysis independent of prior physiological hypotheses. METHODS: We completed a genomewide linkage scan to map loci increasing risk for DSM-IV ND and for a quantitative assessment of ND as measured by the Fagerstrom Test for Nicotine Dependence (FTND) in a set of 634 small nuclear families ascertained on the basis of multiple individuals affected with cocaine or opioid dependence. Of these, 507 had at least two subjects affected with ND. There are two distinct populations within this sample, European-Americans (EAs) and African-Americans (AAs). RESULTS: A region on chromosome 5 was identified as containing a gene that affects risk for ND on the basis of FTND score in the AA part of our sample (logarithm of the odds [lod] score 3.04; empirically determined to be genomewide-significant, p = .0374; point p = .0001). The highest lod score observed in the EA part of the sample was on chromosome 7 (lod score 2.73). Several other "possible" risk loci were identified in either AA or EA subjects, with many of these in proximity to previously suggested risk loci from other clinical samples. Three nominally significant single-nucleotide polymorphism associations were found at the peptidylglycine alpha-amidating monooxygenase (PAM) locus under the chromosome 5 linkage peak, also in the AA part of the sample. CONCLUSIONS: These data add to the growing evidence for locations for ND risk loci, add a novel statistically significant locus important in AAs, and suggest a gene that might be contributing to this linkage signal.

Chromosome Mapping↗

Intronic variants in the dopa decarboxylase (DDC) gene are associated with smoking behavior in European-Americans and African-Americans.

We report here a study considering association of alleles and haplotypes at the DOPA decarboxylase (DDC) locus with the DSM-IV diagnosis of nicotine dependence (ND) or a quantitative measure for ND using the Fagerstrom Test for Nicotine Dependence (FTND). We genotyped 18 single nucleotide polymorphisms (SNPs) spanning a region of approximately 210 kb that includes DDC and the genes immediately flanking DDC in 1,590 individuals from 621 families of African-American (AA) or European-American (EA) ancestry. Evidence of association (family-based tests) was observed with several SNPs for both traits (0.0002<or=P<or=0.04). The most significant result was obtained for the relationship of FTND score to SNP rs12718541 (AA families: P=0.002; EA families: P=0.03; all families: P=0.0002) which is in the same intron as the splice site for a neuronal isoform of human DDC lacking exons 10-15. Haplotype analysis did not reveal any SNP combination with stronger evidence for association than rs12718541 alone. Although sequence analysis suggests that rs12718541 may be an intronic splicing enhancer, further studies are needed to determine whether a direct link exists between an alternatively spliced form of DDC and predisposition to ND. These findings confirm a previous report of association of DDC with ND, localize the causative variants to the 3' end of the coding region and extend the association to multiple population groups.

Adult↗

Genomewide linkage scan for opioid dependence and related traits.

Risk of opioid dependence is genetically influenced. We recruited a sample of 393 small nuclear families (including 250 full-sib and 46 half-sib pairs), each with at least one individual with opioid dependence. Subjects underwent a detailed evaluation of substance dependence-related traits. As planned a priori to reduce heterogeneity, we used cluster analytic methods to identify opioid dependence-related symptom clusters, which were shown to be heritable. We then completed a genomewide linkage scan (with 409 markers) for the opioid-dependence diagnosis and for the two cluster-defined phenotypes represented by >250 families: the heavy-opioid-use cluster and the non-opioid-use cluster. Further exploratory analyses were completed for the other cluster-defined phenotypes. The statistically strongest results were seen with the cluster-defined traits. For the heavy-opioid-use cluster, we observed a LOD score of 3.06 on chromosome 17 (empirical pointwise P = .0002) for European American (EA) and African American (AA) subjects combined, and, for the non-opioid-use cluster, we observed a LOD score of 3.46 elsewhere on chromosome 17 (empirical pointwise P = .00002, uncorrected for multiple traits studied) for EA subjects only. We also identified a possible linkage (LOD score 2.43) of opioid dependence with chromosome 2 markers for the AA subjects. These results are an initial step in identifying genes for opioid dependence on the basis of a genomewide investigation (i.e., a study not conditioned on prior physiological candidate-gene hypotheses).

Adult↗

Risk factors for cocaine-induced paranoia in cocaine-dependent sibling pairs.

OBJECTIVE: Cocaine-induced paranoia (CIP), an irrational intense suspicion of others, is a common manifestation of cocaine dependence. Both environmental and genetic factors are thought to play a role, but the specific nature of such contributions is poorly understood. METHODS: Demographic, diagnostic, and cocaine-use data were obtained from 420 cocaine-dependent, genetically confirmed, full-sibling pairs (N=840 subjects) interviewed with the Semi-Structured Assessment for Drug Dependence and Alcoholism (SSADDA). Probands with and without CIP were compared; then, factors associated with sibling CIP status were analyzed by logistic regression. Alcohol dependence, a known heritable phenotype, was analyzed as a positive control. RESULTS: Of 420 probands, 273 (65%) experienced CIP. Probands with CIP were more severely dependent upon cocaine, had an earlier age of onset, were more likely to smoke cocaine, and used cocaine less frequently during the preceding year. Independent analyses of siblings replicated two of the former (i.e., dependence severity and age of onset). Probands with CIP also had a non-significantly higher proportion of siblings with the trait (66% versus 59%). Probands with concurrent alcohol dependence were confirmed to have significantly higher rates of alcoholism among their siblings. CONCLUSIONS: Severity of cocaine dependence and age of onset appear to be important risk factors for CIP. Concordance for CIP between siblings did not emerge as significant in our analyses.

Adult↗

Genomewide linkage scan for cocaine dependence and related traits: significant linkages for a cocaine-related trait and cocaine-induced paranoia.

Risk for cocaine dependence (CD) is genetically influenced. We recruited a sample of small nuclear families (528 full and 155 half sibpairs) with at least one subject affected with CD. The sample was classified via Bayesian clustering as 45.5% European American (EA) and 54.5% African American (AA). Assessment, via the Semi-Structured Assessment for Drug Dependence and Alcoholism, allowed for detailed evaluation of substance dependence-related traits. To define subgroups with increased genetic homogeneity, consistent with our a priori analytic plan, we used cluster analytic methods to identify six cocaine-related symptom clusters; membership was shown to be significantly heritable. We then completed a genomewide linkage scan (409 markers) for the CD diagnosis, cocaine-induced paranoia (CIP; an outcome that occurs in some cocaine users) and the clusters (three of which contained >80% of the CD subjects). We observed a "suggestive" linkage signal on chromosome 10 for the trait of CD in the full sample; and two "suggestive" linkage signals at different locations on chromosome 3, in the EA part of the sample. We observed a genomewide-significant lod score of 3.65 for the trait of CIP on chromosome 9, in the AA part of the sample only. Our strongest results were observed for the cluster membership traits, including a lod score of 4.66 for membership in the "Heavy Use, Cocaine Predominant" cluster on chromosome 12 (in EAs only) and a lod score of 3.35 for membership in the "Moderate Cocaine and Opioid Abuse" cluster on chromosome 18. These results provide a basis for the identification of specific genes contributing to risk for these traits.

Adult↗

Complement factor H polymorphism and age-related macular degeneration.

Age-related macular degeneration (AMD) is a common, late-onset, and complex trait with multiple risk factors. Concentrating on a region harboring a locus for AMD on 1q25-31, the ARMD1 locus, we tested single-nucleotide polymorphisms for association with AMD in two independent case-control populations. Significant association (P = 4.95 x 10(-10)) was identified within the regulation of complement activation locus and was centered over a tyrosine-402 --> histidine-402 protein polymorphism in the gene encoding complement factor H. Possession of at least one histidine at amino acid position 402 increased the risk of AMD 2.7-fold and may account for 50% of the attributable risk of AMD.

Aged↗