Brain-Derived Neurotrophic Factor Val/Met Polymorphism and Bipolar Disorder

• Published in: Neuropsychobiology Vol. 58; no. 2; pp. 97 - 103
• Main Authors: Kim, Byungsu, Kim, Chang Yoon, Hong, Jin Pyo, Kim, Seong Yoon, Lee, Chul, Joo, Yeon Ho
• Format: Journal Article
• Language: English
• Published: Basel, Switzerland S. Karger AG 01.10.2008
• Subjects: Original Paper; Suicide; Bipolar disorder; Brain-derived neurotrophic factor
• ISSN: 0302-282X; 1423-0224
• DOI: 10.1159/000162356

Background/Aims: The substitution of valine by methionine in the brain-derived neurotrophic factor (BDNF Val/Met) gene alters the intracellular trafficking and regulated secretion of BDNF. This study tested whether the BDNF Val/Met polymorphism is associated with bipolar disorder in Korean subjects, and whether clinical features vary according to genotype. Methods: The allelic and genotypic distributions of BDNF Val/Met were determined in a population of 169 bipolar patients and 251 normal controls. Between-genotype comparisons of clinical features were performed without a priori knowledge of the genotype of individual patients. Results: Allelic distributions did not differ significantly between bipolar patients and controls (χ 2 = 0.400, p = 0.821). However, the rate of suicide attempts among the Val/Val (11.3%), Val/Met (28.8%) and Met/Met (38.9%) genotype groups were significantly different (χ 2 = 9.879, p = 0.007). Relative to patients with the Val/Val genotype, those with the Met/Met genotype had a 4.9-fold higher risk of suicide attempts (95% CI, 1.7–14.7). Conclusions: These findings suggest that BDNF Val/Met is related to the suicidal behavior of bipolar patients, and may have clinical relevance as a biological indicator of bipolar patients at risk of suicide.