title: Possible parent-of-origin effect of Dopa decarboxylase in susceptibility to bipolar affective disorder.
abstract: Dopa decarboxylase (DDC) catalyses the synthesis of both dopamine and serotonin as well as trace amines suggested to possess neuromodulating capabilities. We have previously reported evidence suggesting an association between DDC and bipolar affective disorder (BPAD) [Børglum et al., 1999]. To further investigate the possible role of DDC in BPAD, we analyzed a 1- and a 4-bp deletion variant-both of putative functional significance-in two new samples: a case-control sample with 140 cases and 204 controls, and 100 case-parents trios. We also tested for association in subjects with familial disease in both the new and the previously investigated samples. The previously reported association was not replicated in either of the new samples. However, a preponderance of the 1-bp deletion was increased by analysis of the familial cases separately for all case-control samples investigated, indicating a possible association with familial disease (combined analysis, P = 0.02). In the trio sample, a preferential paternal transmission of the 4-bp deletion was observed (P = 0.006). DDC is located next to the imprinted gene GRB10, which is expressed specifically from the paternal allele in fetal brains. Increased transmission of paternal DDC alleles has also been suggested in attention deficit hyperactivity disorder. We suggest that DDC might confer susceptibility to BPAD predominantly when paternally transmitted.
authors.affiliation: Institute of Human Genetics, University of Aarhus, Denmark. anders@humgen.au.dk
authors.forename: A D
authors.initials: AD
authors.lastname: Børglum
authors.forename: G
authors.initials: G
authors.lastname: Kirov
authors.forename: N
authors.initials: N
authors.lastname: Craddock
authors.forename: O
authors.initials: O
authors.lastname: Mors
authors.forename: W
authors.initials: W
authors.lastname: Muir
authors.forename: V
authors.initials: V
authors.lastname: Murray
authors.forename: I
authors.initials: I
authors.lastname: McKee
authors.forename: D A
authors.initials: DA
authors.lastname: Collier
authors.forename: H
authors.initials: H
authors.lastname: Ewald
authors.forename: M J
authors.initials: MJ
authors.lastname: Owen
authors.forename: D
authors.initials: D
authors.lastname: Blackwood
authors.forename: T A
authors.initials: TA
authors.lastname: Kruse
mesh_terms: D001714:Bipolar Disorder / Q000201:enzymology / Q000235:genetics*; D016022:Case-Control Studies; D004296:Dopa Decarboxylase / Q000235:genetics*; D005192:Family Health; D016368:Frameshift Mutation; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D018392:Genomic Imprinting; D005838:Genotype; D006801:Humans; D040582:Inheritance Patterns; D012606:Scotland; D017384:Sequence Deletion; D014852:Wales
chemical_list: D004296:Dopa Decarboxylase