Monoamine oxidase A is a mitochondrial enzyme involved in the degradation of certain neurotransmitter amines: serotonin and norepinephrine. As for its role in aggression, impulsivity, suicide and mood liability, monoamine oxidase A can be considered a functional candidate in borderline personality disorder.
To test for this hypothesis we genotyped two polymorphic markers in monoamine oxidase A gene, a promoter VNTR and an rs6323 (T941G) in exon 8, in 111 Caucasian borderline personality disorder patients and 289 Caucasian healthy controls. Association analyses using individual marker and haplotype data were performed by a program of COCAPHASE in UNPHASED (MRC Human Genome Mapping Project Resource Centre, Cambridge, UK).
We found that the borderline personality disorder patients had a high frequency of the high activity VNTR alleles (χ2=4.696, P=0.03) and a low frequency of the low activity haplotype (χ2=5.089, P=0.02).
These results show that the monoamine oxidase A gene may play an important role in the etiological development of the borderline personality disorder.