SCHIZOPHRENIA AND BIPOLAR DISORDER GENETIC LINK EXPLORED
New research shows a possible genetic link between schizophrenia and bipolar disorder. Scientists from the University of Cambridge in the United Kingdom investigated abnormalities in the expression of oligodendrocyte-specific and myelin-related genes in the preserved brains of 15 people who had schizophrenia, 15 people who had bipolar disorder and a control group of 15 brains from people who had neither disorder. Using two sensitive mRNA-based techniques, the researchers observed a high degree of overlap of gene-expression changes in both disorders, as well as a clear reduction of oligodendrocyte-related and myelin-related genes. "The high degree of correlation between the expression changes in schizophrenia and bipolar disorder provides compelling evidence for common pathophysiological pathways that may govern the disease phenotypes of schizophrenia and bipolar disorder," commented the study's lead author. This study appeared this week's issue of the journal Lancet.
BLOOD TEST REVEALS LUNG CANCER RISK
A simple blood test will be able to determine which smokers are at an especially high risk of developing lung cancer. Scientists at the Weizmann Institute have discovered a new genetic risk factor that increases the susceptibility of smokers to lung cancer. The genetic marker, called OGG1, is responsible for DNA repair. The researchers were able to develop a new blood test that allowed them to measure the activity level of OGG1. In individuals with low OGG1 activity, damaged DNA is left unrepaired, which can lead to cancer. Smokers who have a low level of OGG1 activity are 5 times to 10 times more likely than other smokers to develop lung cancer, and 120 times more likely to develop lung cancer than non-smokers with normal levels of OGG1 activity. These findings suggest a substantial number of lung cancer cases may result from a combination of smoking and reduced OGG1 activity. This study appeared in the Sept. 2 issue of the Journal of the National Cancer Institute.
GENETICALLY ENGINEERED MOUSE RESISTS DIABETES
A mouse known to be immune to the weight gain associated with a high-calorie, high-fat diet also is able to resist diabetes. Scientists from the University of Wisconsin-Madison made the discovery while studying a mouse stripped of a gene called SCD-1, which produces the enzyme SCD that affects the production of fatty acids. The mouse apparently is impervious to the negative effects of the type of diet that, for many people, has significant health and social consequences. In many instances, obesity and diabetes go hand in hand. The discovery of a gene that seems to exercise significant influence over both weight gain and glucose regulation promises a potentially significant window into both conditions and their relationship. "We are beginning to suspect that obese individuals have increased expression of this enzyme. If you reduce expression of this enzyme, you reduce fat expression in muscle," said one investigator. This study appeared in the Sept. 1 online edition of the Proceedings of the National Academy of Sciences.
RESEARCHERS FIND SECOND CHROMOSOME FOR RARE DISORDER
Researchers have discovered a second site for a gene or genes that cause Joubert syndrome. Investigators from the University of California, San Diego, identified the site on chromosome 11 after focusing on three Middle Eastern families whose relatives had intermarried and passed the genetic defect to several family members. Prior to this study, chromosome 9 had been the only known site with gene mutations causing the disorder. "The main problem in identifying genes has been the small number of patients appropriate for genetic analysis," commented one of the study's lead authors. Joubert syndrome is characterized by the absence or underdevelopment of a brain region called the cerebellar vermis, and by a malformed brain stem. The syndrome affects individuals to varying degrees across the spectrum of motor and mental development. This study was published in the September online edition of the American Journal of Human Genetics.
FIRST MOUSE MODEL FOR KIDNEY STONES
Scientists have developed the first mouse model for cystinuria type I, more commonly known as kidney stones. The model was developed by Ingenium Pharmaceuticals AG using a chemical process that generates point mutations in genes. The researchers located the mutation responsible for the disease state in the SIc3a1 gene. Mutations in the human SIc3a1 gene have long been associated with cystinuria, demonstrating a direct link and further validating the genetically engineered mouse as a model for cystinuria type I disease research. The mouse model also included the presence of relatively large calculi or "stones" in the urinary tract of the animal. "The goal of our research is to better understand the molecular pathway involved with cystinuria type I and this model is a welcome addition because it is the first model that so closely mimics the human disease state," commented one noted urologist. This study appeared in the Sept. 3 edition of the journal Human Molecular Genetics.
(EDITORS: For SCHIZOPHRENIA, contact Joe Santangelo at (212) 633-3810 or [email protected]. For LUNG CANCER, contact Alex Smith at (212) 460-0563 or [email protected]. For DIABETES, contact James Ntambi at (608) 265-3700 or [email protected]. For CHROMOSOME, contact Sue Pondrom at (619) 543-6163 or [email protected]. For KIDNEY, contact Gretchen Schweitzer at 49-89-8565-2398 or [email protected].
