A preliminary study on the relationship of the monoamine oxidase A gene polymorphism and the gray matter concentration in patients with major depressive disorders / 中华行为医学与脑科学杂志

ABSTRACT

Objective To explore the impact of the variable number of tandem repeats of monoamine oxidase A gene (MAOA-uVNTR) on the concentration of gray matter in patients with major depressive disorders.Methods 56 cases of depression, as well as 37 healthy controls who were matched in gender, age and years of education were divided into low-activity genotype (3R or 3R/4R), and high-activity genotype (4R) with the methods of polymerase chain reaction (PCR) amplification and 1.5％ agarose gel electrophoresis separation. 93 cases all were performaned structural magnetic resonance imaging scanning. Results ① The difference of genotype and allele frequency between the depression group and the healthy group was not statistically significant(P＞0.05 ). ②Compared with the healthy,the concentration of gray matter( GMC ) of bilateral caudate nucleus (K = 11/68, Z =3.76/4.76 ), bilateral thalamus ( K = 21/181, Z = 3.26/3.63 ) and right hypothalamus ( K = 38/12, Z = 4.20/3.60) reduced significantly in depressed patients. ③ In patients with depression, cases with the high-activity genotype showed reduced GMC bilateral caudate nucleus (K = 17/33, Z = 3.23/4.36 ), left putamen ( K = 16, Z =3.42 ) and right hypothalamus( K = 12, Z = 3.62 ) in comparision with patients with low-activity genotype. In highactivity genotype group,compared with the healthy,patients with depression had reduced GMC in left caudate nucleus ( K = 11, Z = 4.13 ), bilateral thalamus ( K = 13/14, Z = 3.53/3.23 ) and left parahippocampal gyrus ( K = 13,Z = 4.04). Conclusion High-activity genotype may be an important factor contributing to the structural abnormalitily of the limbic-striatum-globus pallidus-thalamus loop.