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 WAKE-UP provides new treatment option for stroke patients | International study led by UKE
17.05.2018 | Universitätsklinikum Hamburg-Eppendorf

nachricht First form of therapy for childhood dementia CLN2 developed
25.04.2018 | Universitätsklinikum Hamburg-Eppendorf

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: Molecular switch will facilitate the development of pioneering electro-optical devices

A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.

The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

First chip-scale broadband optical system that can sense molecules in the mid-IR

24.05.2018 | Physics and Astronomy

Beyond the limits of conventional electronics: stable organic molecular nanowires

24.05.2018 | Power and Electrical Engineering

These could revolutionize the world

24.05.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>