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Archive - Oct 19, 2019

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Cystic Fibrosis Carriers at Increased Risk of Digestive Symptoms

Researchers have found that carriers of the most common genetic variant that causes cystic fibrosis experience some symptoms similar to those of people with cystic fibrosis. These findings were enabled by large-scale genomic data made available just a few years ago. Yu-Chung (Jerry) Lin, BA, MSc, a graduate student at the University of Toronto, presented the research on October 17, 2019 at the American Society of Human Genetics (ASHG) 2019 Annual Meeting in Houston, Texas (October 15-19). The presentation abstract is titled “Defining the Phenotypic Signature of CFTR Mutation Carriers in the UK Biobank.” Cystic fibrosis is a recessive disease caused by variants of the CFTR gene, which means that affected individuals have two such variants. It affects many organs, and symptoms vary from patient to patient. They can include lung function decline, intestinal obstruction, diabetes, and pancreatic dysfunction. The extent of a person’s symptoms can be affected by modifier genes, which do not directly cause cystic fibrosis, but can affect how an individual’s experience of the disease. Researchers have long assumed that carriers, who have one copy of a disease-causing CFTR variant, do not experience any symptoms. However, given the disease’s wide breadth of symptoms, Mr. Lin explained, researchers needed a very large sample size to definitively answer this question. Senior author Lisa Strug, PhD, Associate Director of The Centre for Applied Genomics at The Hospital for Sick Children, explained, “Although many individuals are learning of their CFTR carrier status through family planning or the use of personal genomics companies, researchers have not yet thoroughly investigated whether a phenotype for cystic fibrosis carriers exists.”

Metabolic Dysfunction in Mitochondria & Not Protein Accumulation Is Key Cause of Alzheimer’s Disease, New Study Shows; Common Anti-Diabetes Drug (Metformin) Identified As Potential Treatment

A team of researchers led by Yale-National University of Singapore (NUS) College scientists has found evidence that metabolic dysfunction is a primary cause of Alzheimer’s disease. Alzheimer’s disease is the most common neurodegenerative disease affecting the elderly worldwide, as well as one of the most common causes of dementia. In Singapore, 1 in 10 people aged 60 or above is believed to suffer from dementia. After more than twenty years of research effort worldwide, scientists are still unable to identify the exact causes of Alzheimer’s and no proven treatment is available. Two competing theories are currently proposed to explain the cause of Alzheimer’s: the first is focused on the accumulation of a specific protein, called amyloid-beta protein, in the brain as the primary cause; whilst a second and more recent theory proposes that metabolic dysfunction, specifically a dysfunction of the cell’s energy-producing machinery called mitochondria is responsible. In a new study published online on October 18, 2019 in eLife (https://elifesciences.org/articles/50069), a team led by Assistant Professor of Science (Biochemistry) Jan Gruber, PhD, from Yale-NUS College discovered that metabolic defects occur well before any significant increase in the amount of amyloid-beta protein could be detected. The open-access article is titled "Metabolic Stress Is a Primary Pathogenic Event In Transgenic Caenorhabditis Elegans Expressing Pan-Neuronal Human Amyloid Beta." The research used a tiny worm called Caenorhabditis elegans to identify these changes because this worm shares many similarities at the molecular level with human cells.