Researchers Locate Genetic Link for Nicotine Dependence Among African Americans

Scientists at the University of Virginia Health System have identified, for the first time ever, several genetic regions that are likely to carry the genes for nicotine dependence (ND) in an African American population. This is the first genome-wide study of such linkage and included the largest group of African Americans to participate in this type of linkage study. Until this study, participants in research to find genetic links to ND have been primarily of European origin.

This new study is important because there are known differences in smoking patterns and in ND risk across ethnic groups. Analysis of twin studies on smoking behavior showed that genetic factors are responsible for at least 50 percent of a person’s tendency toward dependence on nicotine.

“Identifying the genes that predispose a person to nicotine dependence and understanding the molecular mechanisms are vital to prevention and treatment,” said lead author Ming Li, Ph.D., associate professor and head of the Neurobiology Section of the UVa Department of Psychiatric Medicine. "Given the potential ethnic differences in smoking patterns and nicotine metabolism, this study may suggest strategies for identifying genes for tobacco dependence, especially among African American smokers.” This could lead to potential targeted treatments in the future.

Such genome-wide studies are arduous, but they yield valuable information. “Without knowing these regions, we would have no place to start, given that everybody has 22 autosomal chromosomes and two sex chromosomes with about 40,000 genes located throughout the genome,” Dr. Li explained.

The researchers conducted a genome-wide scan of 1,261 individuals representing 402 nuclear families of African American origin, the largest sample collection of African-American smokers throughout the world. Their results revealed a region on chromosome 10 that showed a significant linkage to smoking quantity and other measures of smoking dependence. They also identified three other regions that met the criteria for linkage to at least one ND measure. Some of these regions have been linked to smoking behavior previously, which adds supporting data to the previous studies of nicotine dependence in other populations.

The article, which appears in the October issue of American Journal of Human Genetics (vol. 79, pages 745-751) noted that these linkage regions represent excellent candidate locations that might in the future become targets for treatments that could change a person’s tendency toward using nicotine. To identify susceptibility genes for ND from these regions, the UVa researchers have started a series of genetic analyses using a combination approach of fine mapping and genetics association studies.

To read the article, visit:

http://www.journals.uchicago.edu/AJHG/journal/issues/v79n4/43856/43856.web.pdf

Source: University of Virginia

Related stories:

New neuroimaging study identifies 'brain signature' for cigarette cravings
A new brain imaging study by researchers in the Abramson Cancer Center of the University of Pennsylvania shows that cigarette cravings in smokers who are deprived of nicotine are linked with increased activation in specific regions of the brain.
Studies identify DNA regions linked to nicotine dependence
Americans are bombarded with antismoking messages, yet at least 65 million of us continue to light up. Genetic factors play an important role in this continuing addiction to cigarettes, suggest scientists at Washington University School of Medicine in St. Louis.
Future risk of hurricanes: The role of climate change
Researchers are homing in on the hurricane-prone Gulf of Mexico and Caribbean Sea to assess the likely changes, between now and the middle of the century, in the frequency, intensity, and tracks of these powerful storms. Initial results are expected early next year.
ADHD stimulant treatment may decrease risk of substance abuse in adolescent girls
Massachusetts General Hospital (MGH) researchers have found that treatment with stimulant drugs does not increase and appears to significantly decrease the risk that girls with ADHD will begin smoking cigarettes or using alcohol or drugs. Their report in the October Archives of Pediatrics and Adolescent Medicine parallels the findings of several earlier studies in boys, which needed to be confirmed in girls.
Water table depth tied to droughts in Great Plains
(PhysOrg.com) -- Will there be another “dust bowl” in the Great Plains similar to the one that swept the region in the 1930s? It depends on water storage underground. Groundwater depth has a significant effect on whether the Great Plains will have a drought or bountiful year.
Parental warning: second-hand smoke may trigger nicotine dependence symptoms in kids
Parents who smoke cigarettes around their kids in cars and homes beware – second-hand smoke may trigger symptoms of nicotine dependence in children. The findings are published in the September edition of the journal Addictive Behaviors in a joint study from nine Canadian institutions.
Africa awash in sunlight, but not solar energy
From household solar panels to thermal generators big enough to power a town, sun power has enjoyed explosive growth around the world. Everywhere, that is, except on the sun-drenched continent of Africa.
Survey: 'Tanorexia' common among university students
A new study conducted at a large university finds more than 25 percent of those surveyed reported symptoms of tanning dependence, including symptoms similar to alcohol and drug-addicted individuals. Suggestively, the study also found those with a tanning dependence tend to be more likely to be thin and smoke cigarettes than others. The study by researchers at Fox Chase Cancer Center is published in the September/October issue of the American Journal of Health Behavior.

News discussion:

Medicine & Health news