title: Possible control of dopamine beta-hydroxylase via a codominant mechanism associated with the polymorphic (GT)n repeat at its gene locus in healthy individuals.
abstract: Six allelic fragments were typed by a PCR-based process with a pair of primers specific for a sequence containing the polymorphic (GT)n repeat at the human dopamine beta-hydroxylase (DBH) locus in 125 unrelated healthy individuals. Their frequencies among these individuals were 0.012 (A1), 0.08 (A2), 0.344 (A3), 0.548 (A4), 0.004 (A5) and 0.012 (A6); the two major alleles, A3 and A4, made up nearly 90% of the alleles. These individuals were divided into four groups according to the genotype they possessed, i.e. A3/A3, A4/A4, A3/A4 and others (mixed group). Kruskal-Wallis analysis revealed a significant difference in serum DBH activity among these four genetic groups (H = 32.7, P < 0.0001). The homozygotic genotypes, A3/A3 and A4/A4, were associated with low and high DBH activity, respectively, and the heterozygotic genotype, A3/A4, seemed to play a role in keeping the DBH activity at a moderate level. The present work suggests that the human DBH is likely to be controlled via a codominant mechanism associated with the dinucleotide repeat polymorphism at its gene locus.
authors.affiliation: Institute of Biological Psychiatry, Schizophrenia Association of Great Britain, Bangor, Gwynedd, UK. jwei@hgmp.mrc.ac.uk
authors.forename: J
authors.initials: J
authors.lastname: Wei
authors.forename: C N
authors.initials: CN
authors.lastname: Ramchand
authors.forename: G P
authors.initials: GP
authors.lastname: Hemmings
mesh_terms: D000483:Alleles; D001483:Base Sequence; D017931:DNA Primers; D018900:Dinucleotide Repeats; D004299:Dopamine beta-Hydroxylase / Q000097:blood / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D012016:Reference Values
chemical_list: D017931:DNA Primers; D004299:Dopamine beta-Hydroxylase