Brain-derived neurotrophic factor (Val66Met) polymorphism and olfactory ability in young adults

Background: brain- derived neurotrophic factor (bdnf) is linked to neurodegenerative diseases (e.g. alzheimer disease and parkinson disease) which are often characterized by olfactory impairment. a specific single nucleotide polymorphism of the bdnf gene,the val66met,modulates intracellular trafficking and activity-dependent secretion of bdnf protein. the aim of this study was to investigate a possible association between brain- derived neurotrophic factor val66met polymorphism and olfactory function,a well-known biomarker for neurodegeneration,in healthy young adults. a total of 101 subjects (45 males,age 38.7 ± 9.4 years) were assessed using the sniffin' sticks extended test,a highly reliable commercial olfactory test composed of three sub-parts,calculating olfactory threshold (sensitivity),odor discrimination and odor identification. the val66met polymorphism was determined by polymerase chain reaction -restriction fragment length polymorphism (pcr-rflp) analysis. results: an impaired function in met carriers was found,especially when compared to subjects with val/val genotype,in the threshold (5.5 ± 2.0 vs 6.5 ± 1.8,p = 0.009),discrimination (10.3± 2.5 vs 11.9 ± 2.2,p = 0.002),and identification task (13.3 ± 1.6 vs 14.1 ± 1.3,p = 0.007),as well as in the overall tdi score (29.1 ± 4.5 vs 32.6 ± 3.9,p < 0.001). conclusions: these findings appear to have implications for the evaluation of olfactory function and the relation of its impairment to cognitive decline and neurodegenerative disease. © 2013 tonacci et al.; licensee biomed central ltd.