Biomedical subjects

L Charbonneau

Publications and source records attributed to L Charbonneau.

At least 19 recordsLinked to original sources

PubMed1995

Mapping of the serotonin 5-HT1D beta autoreceptor gene on chromosome 6 and direct analysis for sequence variants.

Abnormal brain serotonin function may be characteristic of several neuropsychiatric disorders. Thus, it is important to identify polymorphic genes and screen for functional variants at loci coding for genes that control normal serotonin functions. 5-HT1D beta is a terminal serotonin autoreceptor which may play a role in regulating serotonin synthesis and release. Using an SSCP technique we screened for 5-HT1D beta coding sequence variants in psychiatrically interviewed populations, which included controls, alcoholics, and alcoholic arsonists and alcoholic violent offenders with low CSF concentrations of the main serotonin metabolite 5-HIAA. A common polymorphism was identified in the 5-HT1D beta gene with allele frequencies of 0.72 and 0.28. The SSCP variant was caused by a silent G to C substitution at nucleotide 861 of the coding region. This polymorphism could also be detected as a HincII RFLP of amplified DNA. DNAs from informative CEPH families were typed for the HincII RFLP and analyzed with respect to 20 linked markers on chromosome 6. Multipoint analysis placed the 5-HT1D beta receptor gene between markers D6S286 and D6S275. A maximum two-point lod score of 10.90 was obtained to D6S26, which had been previously localized on 6q14-15. Chromosomal aberrations involving this region have been previously shown to cause retinal anomalies, developmental delay, and abnormal brain development. This region also contains the gene for North Carolina-type macular dystrophy.

Alcoholism↗

PubMed1994

Polymorphic admixture typing in human ethnic populations.

A panel of 257 RFLP loci was selected on the basis of high heterozygosity in Caucasian DNA surveys and equivalent spacing throughout the human genome. Probes from each locus were used in a Southern blot survey of allele frequency distribution for four human ethnic groups: Caucasian, African American, Asian (Chinese), and American Indian (Cheyenne). Nearly all RFLP loci were polymorphic in each group, albeit with a broad range of differing allele frequencies (delta). The distribution of frequency differences (delta values) was used for three purposes: (1) to provide estimates for genetic distance (differentiation) among these ethnic groups, (2) to revisit with a large data set the proportion of human genetic variation attributable to differentiation within ethnic groups, and (3) to identify loci with high delta values between recently admixed populations of use in mapping by admixture linkage disequilibrium (MALD). Although most markers display significant allele frequency differences between ethnic groups, the overall genetic distances between ethnic groups were small (.066-.098), and < 10% of the measured overall molecular genetic diversity in these human samples can be attributed to "racial" differentiation. The median delta values for pairwise comparisons between groups fell between .15 and .20, permitting identification of highly informative RFLP loci for MALD disease association studies.

Alleles↗

PubMed1992