from "New Study Finds Increased HIV Susceptibility Gene For Africans," Alex Garrel
According to the results of a recent AIDS-oriented study performed by an international team of researchers, black individuals present a gene variant which, while ensuring a higher level of protection against some types of malaria, increases the body’s vulnerability to HIV infection by 40 percent.
The study leader was Dr. Sunil Ahuja, a professor of infectious diseases from the University of Texas Health Science Center at San Antonio. The results and compiled data were published in Cell Host & Microbe on Wednesday.
Here is a sample from the research summary:
published in Cell Host and Microbe, Vol 4, 52-62, 17 July 2008, Copyright © 2008 Cell Press. All rights reserved:
Duffy antigen receptor for chemokines (DARC) expressed on red blood cells (RBCs) influences plasma levels of HIV-1-suppressive and proinflammatory chemokines such as CCL5/RANTES. DARC is also the RBC receptor for Plasmodium vivax. Africans with DARC −46C/C genotype, which confers a DARC-negative phenotype, are resistant to vivax malaria. Here, we show that HIV-1 attaches to RBCs via DARC, effecting trans-infection of target cells. In African Americans, DARC −46C/C is associated with 40% increase in the odds of acquiring HIV-1. If extrapolated to Africans, ∼11% of the HIV-1 burden in Africa may be linked to this genotype. After infection occurs, however, DARC-negative RBC status is associated with slower disease progression. Furthermore, the disease-accelerating effect of a previously described CCL5 polymorphism is evident only in DARC-expressing and not in DARC-negative HIV-infected individuals. Thus, DARC influences HIV/AIDS susceptibility by mediating trans-infection of HIV-1 and by affecting both chemokine-HIV interactions and chemokine-driven inflammation.(click here for the full report)
Violence and delinquency as genetic tendencies
from "Study finds genetic link to violence, delinquency," Maggie Fox, Health and Science Editor, Reuters
Three genes may play a strong role in determining why some young men raised in rough neighborhoods or deprived families become violent criminals, while others do not, U.S. researchers reported on Monday. One gene called MAOA that played an especially strong role has been shown in other studies to affect antisocial behavior -- and it was disturbingly common, the team at the University of North Carolina reported.
People with a particular variation of the MAOA gene called 2R were very prone to criminal and delinquent behavior, said sociology professor Guang Guo, who led the study.
"I don't want to say it is a crime gene, but 1 percent of people have it and scored very high in violence and delinquency," Guo said in a telephone interview.
His team, which studied only boys, used data from the National Longitudinal Study of Adolescent Health, a U.S. nationally representative sample of about 20,000 adolescents in grades 7 to 12. The young men in the study are interviewed in person regularly, and some give blood samples. Guo's team constructed a "serious delinquency scale" based on some of the questions the youngsters answered.
"Nonviolent delinquency includes stealing amounts larger or smaller than $50, breaking and entering, and selling drugs," they wrote in the August issue of the American Sociological Review. "Violent delinquency includes serious physical fighting that resulted in injuries needing medical treatment, use of weapons to get something from someone, involvement in physical fighting between groups, shooting or stabbing someone, deliberately damaging property, and pulling a knife or gun on someone."
[The researchers] found specific variations in three genes -- the monoamine oxidase A (MAOA) gene, the dopamine transporter 1 (DAT1) gene and the dopamine D2 receptor (DRD2) gene -- were associated with bad behavior, but only when the boys suffered some other stress, such as family issues, low popularity and failing school.
MAOA regulates several message-carrying chemicals called neurotransmitters that are important in aggression, emotion and cognition such as serotonin, dopamine and norepinephrine.(more)
