GENETIC 'SIGNATURE' LINKED TO SEVERE LUPUS SYMPTOMS
A team of scientists has discovered a genetic "signature" present in some systemic lupus erythematosus patients. These patients develop life-threatening complications including blood disorders, central nervous system damage and kidney failure. Dr. Timothy W. Behrens of the University of Minnesota, and colleagues from North Shore Long Island Jewish Research Institute, used DNA micro-arrays to analyze thousands of genes in the peripheral blood cells of 48 lupus patients and 42 healthy controls. They found 14 were linked to a subset of SLE patients with severe disease. These 14 genes, referred to collectively as the IFN (interferon) expression signature, are turned on by the activity of interferon, a complex family of proteins involved in regulating immune responses. Behrens says the finding provides strong support for developing therapies to block IFN pathways in patients with severe lupus, as well as identifying patients who will most benefit from these new therapies. The signature also could serve as a marker. The study appears in the online journal Proceedings of the National Academy of Sciences.
ESTROGEN RECEPTOR KEY TO PERSONALITY IN WOMEN
A Swedish study suggests a variation in the estrogen receptor alpha gene may contribute to personality. The researchers investigated a repeat polymorphism in the ER alpha gene in 172 42-year-old women who had been assessed using the Karolinska Scales of Personality. The associations between the ER alpha gene and the factors of neuroticism, psychoticism, non-conformity and extraversion were analyzed. Significant associations were found with the non-conformity factor, including the subscales indirect aggression and irritability, and the factor psychoticism, including the subscale suspicion. There were no significant associations found between the repeat polymorphism in the ER alpha gene and the factors of neuroticism or extraversion. The research is published in the February issue of Molecular Psychiatry.
LEPROSY SUSCEPTIBILITY GENE DESCRIBED
An international research team has identified a gene on human chromosome 6 that makes people vulnerable to leprosy. While leprosy is rare in the United States and Canada, the World Health Organization has identified 91 countries in which the infectious disease is highly prevalent. Researchers used "genome scanning" to map the gene, analyzing DNA samples from nearly 100 families susceptible to the disease. The families all shared a common gene variant on chromosome 6. The researchers also analyzed the DNA of an additional 200 families with leprosy, confirming their findings. "These studies lead the way to developing better treatment and a possible vaccine," says Dr. Marcel Behr, infectious disease specialist at the McGill University Health Center. The team will publish their findings in the March 2003 issue of Nature Genetics.
GENE TARGETING TECHNIQUE EXTENDED
Scientists have developed methods for recombining segments of DNA within human embryonic stem cells. This technique, known as homologous recombination, has long been used to generate mice whose genomes have been modified by eliminating one or more genes. These "knockouts" or genetically altered mice have been essential in the study of gene function in mammals, however, while there are many genetic similarities between mice and humans, they are not identical. There are human genes that differ in clinically significant ways from the corresponding mice genes, according to Thomas Zwaka, a University of Wisconsin-Madison researcher. The ability to use homologous recombination is "one of the essential techniques necessary for human ES cells to fulfill their promise as a basic research tool and has implications for ES cell-based transplantation and gene therapies," write study co-authors Zwaka and James A. Thompson. This new work will allow researchers to simulate gene-based diseases in the lab, and it could help speed the effort to produce cells that can be used therapeutically. The study is in online edition of the journal Nature Biotechnology.
GENETICS OF ALZHEIMER'S WILL PAVE WAY FOR "DESIGNER" TREATMENTS
Alzheimer's screening will be routine in the future, with patients receiving customized medications based on risk. Rudolph E. Tanzi, director of the Genetics and Aging Research Unit at Massachusetts General Hospital in Boston, said researchers have identified 12 potential sites for Alzheimer's genes. Tanzi and other researchers already have identified four different genes that play a role in Alzheimer's disease. Three have been shown to cause the disease known as "early onset" Alzheimer's, while the fourth gene is involved in cholesterol metabolism and is linked to dementia of aging. "As Alzheimer's genes have been uncovered, the biological pathways that become impaired in the disease have gradually become elucidated, paving the way for the development of effective therapies for prevention and treatment of the disease," Tanzi said. The findings were reported Friday at the American Association for the Advancement of Science.
(Editors: For more information about LUPUS, contact Liz Freedman at (301) 496-8190 or firstname.lastname@example.org. For ESTROGEN, Aimee Midei, (310) 206-6739 or MolecularPsychiatry@mednet.ucla.edu, for LEPROSY, Christine Zeindler, (514)934-1934 or email@example.com., for STEM CELLS, Thomas P. Zwaka, (608) 265-3131 or firstname.lastname@example.org., and for ALZHEIMERS, Monica Amarelo, (303) 228-8301 or email@example.com)