New understanding of genetic signature associated with Alzheimer’s disease
Genetic variations in DNA repair patterns may increase risk of pancreatic cancer by as much as threefold or decrease it by as much as 77 percent, depending on the genes involved, according to a report published in the January 15, 2009, issue of Clinical Cancer Research, a journal of the American Association for Cancer Research.
Full Post: Genetic variations in DNA repair patterns may increase risk of pancreatic cancer
Scientists have new information about the complex genetic signature associated with Alzheimer’s disease, the leading cause of cognitive decline and dementia in the elderly.
The research, published by Cell Press in the January issue of the American Journal of Human Genetics , uses a powerful, high-resolution analysis to look for genes associated with this devastating neurodegenerative disorder.
Previous research linked late-onset Alzheimer’s disease, the most common form, with the apolipoprotein E gene. However, the genetics of the disease are complex and are not well understood. “Though apolipoprotein E has been universally confirmed as a risk gene for late-onset Alzheimer’s disease, the gene is neither necessary nor sufficient to cause AD and as much as 50% of the genetic risk effect remains unexplained,” says senior study author Dr. Margaret A. Pericak-Vance from the Miami Institute for Human Genomics at the University of Miami in Florida.
To gain further insight into the genetics of late-onset Alzheimer’s disease, Dr. Pericak-Vance and colleagues completed a sophisticated and comprehensive genetic analysis of 492 late-onset Alzheimer’s disease patients and 498 control individuals. The analysis was powerful enough to detect single nucleotide polymorphisms (SNPs) that are significantly more prevalent in individuals with Alzheimer’s disease than they are in controls. A SNP is a variation of a single nucleotide of DNA.
The researchers confirmed the known apolipoprotein E association and identified a new association with a SNP on chromosome 12q13. The SNP is close to the gene for the vitamin D receptor, which has previously been linked with memory performance. “There is no known connection between this SNP and the vitamin D receptor, but the region between the two is largely uncharacterized, and it is possible that our SNP is in a region that may play some sort of regulatory role,” offers Dr. Jonathan Haines, co-director of the project at Vanderbilt University’s Center for Human Genetics Research.
The team also identified four other regions of interest and validated several candidate genes that exhibited a promising genome-wide association with Alzheimer’s disease. “Detailed functional examination of these signals and genes may lead to a better understanding of the complex pathophysiology of Alzheimer’s disease,” concludes Dr. Pericak-Vance.
Researchers at Mayo Clinic have discovered the first gender-linked susceptibility gene for late-onset Alzheimer’s disease. In the Jan. 11 online edition of Nature Genetics, they report the results of their two-stage genome-wide association study of patients with Alzheimer’s disease. The research showed that women who inherited two copies of a variant in the PCDH11X gene,
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A special issue of American Journal of Medical Genetics (AJMG): Part B: Neuropsychiatric Genetics presents a comprehensive overview of the latest progress in genetic research of Attention Deficit/Hyperactivity Disorder (ADHD). The issue covers major trends in the field of complex psychiatric genetics, underscoring how genetic studies of ADHD have evolved, and what approaches are needed
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Scientists at the MUHC and McGill University have identified a gene essential for the uptake of vitamin B12 in human cells. The discovery of this gene finally completes a 24 year-old hunt for the cause of an incredibly rare genetic disorder called, cblF combined homocystinuria and methylmalonic aciduria (cblF-Hcy-MMA), first documented in a Quebec infant
Full Post: Scientists explain genetic disease first discovered in Quebec 24 years ago
The adult children of people diagnosed with inherited Alzheimer’s disease are the focus of a new study to better understand the biology of the disease. Researchers are seeking 300 volunteers with a biological parent with a known genetic mutation causing rare and typically early-onset forms of the disorder to join the Dominantly Inherited Alzheimer’s
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An international consortium of researchers, including major contribution from a team led by Dr. John D. Rioux, a professor of medicine at the Université de Montréal and the Montreal Heart Institute, has identified genetic markers associated with risk for ulcerative colitis. The findings, published in the advance online journal Nature Genetics , bring researchers closer
Full Post: New genetic markers for ulcerative colitis could lead to treatment