Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

SNPs Affect Folate Metabolism in Study of Puerto Rican Adults

11.11.2008
Tufts researchers have linked several single nucleotide polymorphisms (SNPs) in the DNA of Puerto Rican adults to altered concentrations of blood homocysteine and folate and the content of uracil in blood DNA. These measures are indicators of altered folate metabolism, a putative risk factor for many diseases including cancer and neural tube defects.

Researchers at Tufts University have gained further understanding of the genomic basis for altered folate metabolism and the content of uracil in blood DNA.

In a study published in October’s American Journal of Clinical Nutrition, senior author Jimmy Crott, PhD, and colleagues studied nine single nucleotide polymorphisms (SNPs) in five genes involved in folate uptake and retention: folate hydrolase (FOLH1), folate polyglutamate synthase (FPGS), ã-glutamyl hyrdolase (GGH), proton-coupled folate transporter (PCFT), and reduced folate carrier (RFC1) in a cohort of 991 Puerto Rican adults residing in and around Boston. In addition, four SNPs in two genes involved in folate metabolism previously associated with altered blood folate and homocysteine concentrations were studied: methylenetetrahydrofolate reductase (MTHFR) and methionine synthase (MTR).

SNPs are variations in the sequence of nucleotides, or building blocks, that make up genes. Humans possess two copies of every gene. For each SNP, there are three possible genotypes depending on the presence of “normal” and “variant” copies of the gene; two normal copies, one normal and one variant or two variant copies.

Diseases, such as some cancers, have been associated with diminished blood folate concentrations and abnormal folate metabolism. Crott, a scientist in the Vitamins and Carcinogenesis Laboratory at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts, and first author Lauren DeVos of Pennsylvania State University found that several SNPs affect folate metabolism, as evidenced by altered concentrations of blood homocysteine, folate, and DNA uracil.

“Perhaps the most intriguing results of this study involve these SNPs that affected the concentration of uracil in DNA. Uracil accumulation has the potential to cause DNA breakage, a mutagenic event that may increase the risk for cancer,” Crott said.

With respect to the MTHFR 677C>T SNP, those with two copies of the variant gene (TT genotype) displayed a 33.8% lower blood DNA uracil content than those with one or less copies of a variant gene (CC and CT genotypes). This observation fits with previous work showing that, under certain conditions, those with the TT genotype have a significantly lower risk for colorectal cancer than CC and CT genotypes. In addition, a significant association was detected between the -124T>G SNP in GGH gene and DNA uracil content. Individuals with one copy of the variant GGH gene (-124TG genotype) had DNA uracil levels 30% higher, while those with two copies of the variant gene (-124GG genotype) had a uracil level 73% higher than wildtypes (-124TT genotype). The authors speculate that this change might feasibly increase these individuals’ risk for cancer.

Differences in blood folate concentrations were also associated with two of the SNPs studied. After correcting for other potentially confounding factors, those with the MTHFR 677TT genotype displayed folate concentrations 4.6% lower than CC genotypes and CT genotypes. Those with at least one copy of the variant T gene of the FOLH1 1561C>T SNP had blood folate concentrations 10.8% higher than those with the CC genotype. “Although the changes we see here are rather modest, low blood folate concentrations are associated with several diseases including colorectal cancer and neural tube defects,” Crott said.

This study was a nested cohort within the ongoing Boston Puerto Rican Health Study (BPRHS). Puerto Rican adults between the ages of 45 and 75 were identified in blocks containing at least 10 Hispanic occupants in the 2000 census, and one per household (randomly selected) interviewed in his or her home. In addition to answering health-related and anthropometric questions, participants filled out a population-validated, food-frequency questionnaire.

“The current study is part of a body of research exploring whether a diet lacking essential nutrients like B vitamins and antioxidants plays a role in health disparities in older Puerto Rican adults,” said co-author Katherine Tucker, a professor at the Friedman School of Nutrition Science and Policy, director of the Dietary Assessment and Epidemiology Research Program at the JM USDA HNRCA, and principal investigator of the BPRHS.

“The BPRHS is building on previous Tufts research which demonstrates that older Puerto Rican adults living in Boston are more likely to develop chronic health conditions such as depression and diabetes compared to older non-Hispanic whites living in the same neighborhoods,” Tucker continued. “We hypothesize these health disparities are triggered by stress associated with poverty, perceived discrimination and poor nutrition among other challenges.”

This work was supported in part by grants from the United States Department of Agriculture, the USDA Agricultural Research Service and the National Institutes of Health.

DeVos L, Chanson A, Liu Z, Ciappio ED, Parnell LD, Mason JB, Tucker KL, Crott JW. American Journal of Clinical Nutrition. 2008 (October); Vol 88, Issue 4. “Associations between single nucleotide polymorphisms in folate uptake and metabolizing genes with blood folate, homocysteine and DNA uracil concentrations.”

About Tufts University School of Nutrition

The Gerald J. and Dorothy R. Friedman School of Nutrition Science and Policy at Tufts University is the only independent school of nutrition in the United States. The school's eight centers, which focus on questions relating to famine, hunger, poverty, and communications, are renowned for the application of scientific research to national and international policy. For two decades, the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University has studied the relationship between good nutrition and good health in aging populations. Tufts research scientists work with federal agencies to establish the USDA Dietary Guidelines, the Dietary Reference Intakes, and other significant public policies.

Andrea Grossman | Newswise Science News
Further information:
http://www.tufts.edu

More articles from Studies and Analyses:

nachricht New study: How does Europe become a leading player for software and IT services?
03.04.2017 | Fraunhofer-Institut für System- und Innovationsforschung (ISI)

nachricht Reusable carbon nanotubes could be the water filter of the future, says RIT study
30.03.2017 | Rochester Institute of Technology

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

Bare bones: Making bones transparent

27.04.2017 | Life Sciences

Study offers new theoretical approach to describing non-equilibrium phase transitions

27.04.2017 | Physics and Astronomy

From volcano's slope, NASA instrument looks sky high and to the future

27.04.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>