Preliminary evidence of an association between bipolar disorder in females and the catechol-O-methyltransferase gene.
Catechol-O-methyltransferase (COMT) catalyses the methylation, and hence the inactivation, of catecholamines including the neurotransmitters dopamine and noradrenaline. There is evidence implicating COMT as a candidate gene for a number of neuropsychiatric conditions including bipolar disorder. A long recognized population variation in COMT activity exists and it has recently been established that variation in enzyme activity results from a polymorphic genetic variation within the COMT gene which can be readily assayed as a polymerase chain reaction (PCR)-based restriction fragment length polymorphism (RFLP). A collection of 60 Irish bipolar I probands have been genotyped together with their parents. Tests comparing transmitted and non-transmitted alleles provide no evidence that the polymorphism contributes to a susceptibility to bipolar disorder within the sample as a whole. However, amongst female bipolar I probands (n = 30) there was a tendency for the low-activity allele of COMT to be preferentially transmitted. Furthermore, a re-examination of an Irish case-control sample resulted in a similar observation amongst female bipolar I sufferers and pooling the data sets strengthened the findings.
Mynett-Johnson
L A
LA
Department of Genetics, Trinity College, Dublin, Ireland.
Murphy
V E
VE
Claffey
E
E
Shields
D C
DC
McKeon
P
P
D000483:Alleles; D001714:Bipolar Disorder / Q000201:enzymology / Q000453:epidemiology / Q000235:genetics*; D016022:Case-Control Studies; D002394:Catechol O-Methyltransferase / Q000032:analysis / Q000235:genetics*; D002892:Chromosomes, Human, Pair 22 / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006239:Haplotypes / Q000235:genetics; D006801:Humans; D007494:Ireland / Q000453:epidemiology; D008297:Male; D010290:Parents; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D012150:Polymorphism, Restriction Fragment Length; D012306:Risk
D002394:Catechol O-Methyltransferase