N05041: Genotypes underlying functional bioavailability of selenium
Tuesday 27 July 2004
This research project aims to explore the variation in selenium nutritional requirements of genetically differing sections of the population.
Background
Dietary selenium (Se) is essential for human health. The dietary intake of Se, and the Se status, of the UK population has fallen by 30-50% over the past 15-20 years and such a fall in Se status has potentially very important implications for a range of health issues.
The physiological effects of Se are due to its role in a family of Se containing proteins (selenoproteins). The extent to which individuals in the UK population differ in their ability to utilise available dietary Se for selenoprotein synthesis is not known.
It is hypothesised that there is genetic variation in the key components of the cellular machinery that carries out selenoprotein synthesis and that this leads to variation in functional Se bioavailability and Se requirements for optimal nutrition. The project aims 1] to define the polymorphisms in SBP2, selenophosphate synthetase and SelP genes which exist in the UK population, 2] to determine the frequencies at which such polymorphisms exist in different ethnic groups within the UK and to 3] define whether such polymorphisms affect the functional bioavailability of Se, as assessed by selenoprotein activity and protein levels.
Results from this project will help to define the extent to which genetic polymorphisms (GP) in genes encoding components of the cell machinery for incorporation of Se determine its functional bioavailability in the UK population.
Research Approach
This project will:
- Identify common polymorphisms in gene sequences in SBP2, selenophosphate synthetase and SelP and determine the frequency of these polymorphisms in different UK ethnic groups (caucasian, South Asian, Chinese).
- Determine the frequency of a polymorphism in GPX4 in South Asian and Chinese ethnic groups in the UK.
- Determine whether the identified polymorphisms affect the functional bioavailability of Se in people consuming their usual diet and after Se supplementation.
- Define subgroups of the population which differ in the pattern of Se utilisation by lymphocytes and which would require refined, targeted nutritional advice.