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.
Alessandro
A
Tonacci
Andrea
A
Borghini
Antonella
A
Mercuri
Giovanni
G
Pioggia
Maria Grazia
MG
Andreassi
D000328:Adult; D000544:Alzheimer Disease / Q000235:genetics*; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics*; D005260:Female; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D066194:Olfactory Cortex / Q000473:pathology; D010300:Parkinson Disease / Q000235:genetics* / Q000473:pathology; D020641:Polymorphism, Single Nucleotide
D019208:Brain-Derived Neurotrophic Factor