The Val66Met polymorphism and bipolar disorder in a Mexican sample

  • Dr Federico Diaz-Madrid, Hospital Psiquiatrico Fray Bernardino Alvarez, Mexico
  • Dr Yolanda Ocampo-Mendoza, Instituto Nacional de Psiquiatria Ramon de la Fuente, Mexico
  • Dr Mario Garcia-Alanis, Hospital Psiquiatrico Fray Bernardino Alvarez, Mexico
  • Ms Adriana Balderas-Francisco, Universidad Veracruzana, Veracruz, Mexico
  • Dr Francisco Romo-Nava, Instituto Nacional de Psiquiatria Ramon de la Fuente, Mexico
  • Dr Claudia Becerra-Palars, Instituto Nacional de Psiquiatria Ramon de la Fuente, Mexico
  • Dr Carlos Berlanga-Cisneros, Instituto Nacional de Psiquiatria Ramon de la Fuente, Mexico
  • Dr Adriana Diaz-Anzaldua, Instituto Nacional de Psiquiatria Ramon de la Fuente, Mexico

Introduction Brain-derived neurotrophic factor (BDNF) is involved in neuronal survival and growth. Its relationship with the etiology of bipolar disorder (BD) has been suggested by several lines of study. An association between the Val66Met genetic polymorphism and BD has been reported in other populations.
Objective To determine if there is an association between the Val66Met polymorfphism and type 1 and 2 BD in a mexican sample.
Methods Family-based association study, 207 DNA samples from 86 type-1 or 2 BD patients (SCID-I) and mexican ancestry, and 121 relatives.
Results The Valine allele was extremely frequent in our sample, and no significant association was identified when we analyzed the transmitted (cases) versus non-transmitted (control) alleles (p=0.240053).
Conclusions A low heterozygocity was identified for the Val66Met polymorphism at the BDNF locus in our sample. The Met allele has a frequency of 0 a 72%, depending on the analyzed human population. In our sample, it has a frequency of 15.2%.
References
1.- Binder D., Scharfman H. Brain-derived Neurotrophic Factor. Growth Factors. 2004 September ; 22(3): 123–131.
2.- Neves-Pereira M., et al. The Brain-Derived Neurotrophic Factor Gene Confers Susceptibility to Bipolar Disorder: Evidence from a Family-Based Association Study. Am. J. Hum. Genet. 71:651–655, 2002