Humans normally have 46 chromosomes in each cell, divided into 23 pairs. Two copies of chromosome 21, one copy inherited from each parent, form one of the pairs. Chromosome 21 is the smallest human chromosome, spanning about 47 million base pairs (the building blocks of DNA) and representing approximately 1.5 percent of the total DNA in cells.
In 2000, researchers working on the Human Genome Project announced that they had determined the sequence of base pairs that make up this chromosome. Chromosome 21 was the second human chromosome to be fully sequenced.
Identifying genes on each chromosome is an active area of genetic research. Because researchers use different approaches to predict the number of genes on each chromosome, the estimated number of genes varies. Chromosome 21 likely contains between 300 and 400 genes.
Genes on chromosome 21 are among the estimated 20,000 to 25,000 total genes in the human genome.
Cancer Research UK scientists have discovered cancer-blocking activity for genes carried on chromosome 21 - an extra copy of which is carried by people with Down's syndrome, reveals research published in Nature.
Parents and doctors have known for a long time that children with Down syndrome tend to grow more slowly and are considerably shorter than most other children. But pediatricians needing to record growth milestones at regular office visits have an outdated set of growth charts based on data collected more than 25 years ago.
Conventional wisdom among scientists for years has suggested that because individuals with Down syndrome have an extra chromosome, the disorder most likely results from the presence of too many genes or proteins contained in that additional structure.
Research Down Syndrome has launched an international outreach program to focus awareness and support for the rapidly advancing area of biomedical research leading to safe and effective approved medical therapies to treat cognitive impairment in individuals of all ages with Down syndrome -- improving memory, learning and communication.
Between 5 and 10 percent of babies with Down syndrome develop a transient form of leukemia that usually resolves on its own. However, for reasons that haven't been clear, 20 to 30 percent of these babies progress to a more serious leukemia known as Down syndrome acute megakaryoblastic leukemia (DS-AMKL), which affects the blood progenitor cells that form red blood cells and platelets.
QR Pharma, Inc., a developer of novel drugs to treat Alzheimer’s disease (AD), announced today that it was issued U.S. Patent No. 7,625,942, a "Method of Treating Down Syndrome" by the U.S. Patent and Trademark Office. The '942 patent covers use of Posiphen and analogs to treat cognitive impairments associated with Down Syndrome (DS). This patent valuably expands upon the original Posiphen and analog patent that claims composition of matter and use of compounds to lower amyloid-β precursor protein (APP) and thereby treat dementia and Alzheimer’s disease (AD).
Women experiencing an early onset of menopause could develop dementia at a younger age. Research by Tonnie Coppus of Erasmus MC has indicated this. She studied women with Down Syndrome, who are known to have an early onset of menopause. The results of her research can be translated to apply to the general population. Her results will be published in the Journal of Alzheimer Disease today.
Women experiencing an early onset of menopause could develop dementia at a younger age. Research by Tonnie Coppus of Erasmus MC has indicated this. She studied women with Down Syndrome, who are known to have an early onset of menopause. The
Nearly 20 years ago Huntington Potter kicked up a storm of controversy with the idea that Down syndrome and Alzheimer's were the same disease. Now the evidence is in: He was right.
A study by neuroscientist William C. Mobley, MD, PhD, chair of the Department of Neurosciences at the University of California, San Diego School of Medicine, and colleagues at Stanford University Medical School has demonstrated a possible new approach to slowing the inevitable progression of cognitive decline found in Down's syndrome.
Researchers identified a new chromosomal abnormality in acute lymphoblastic leukemia (ALL) that appears to work in concert with another mutation to give rise to cancer. This latest anomaly is particularly common in children with Down syndrome.
An international team of scientists has identified two more genetic risk factors for Alzheimer's disease. The findings are reported in the online edition of the journal Nature Genetics.
deCODE genetics (Nasdaq: DCGN) today announced its consolidated financial results for the quarter ended June 30, 2009. A conference call to discuss these results and recent developments in the company's business will be webcast live tomorrow, Tuesday, August 11, at 8:00am Eastern Daylight Time/12 noon GMT/1pm British Summer Time (details below).
A discovery by scientists at deCODE genetics and academic colleagues from Iceland, the Netherlands and Denmark has pointed to a common biological mechanism contributing to both kidney stones and decreased bone mineral density (BMD).
A paper published in the Proceedings of the National Academy of Sciences by Tufts Medical Center and Tufts University researchers reports that amniotic fluid surrounding Down syndrome fetuses shows oxidative stress, a condition that could harm fetal cells and play a role in affected individuals. The results demonstrate secondary adverse consequences of Down syndrome and suggest potential prenatal therapies.
Most cancers are rare in people with Down syndrome, whose overall cancer mortality is below 10 percent of that in the general population. Since they have an extra copy of chromosome 21, it's been proposed that people with Down syndrome may be getting an extra dose of one or more cancer-protective genes.
A newly identified molecular pathway that directs stem cells to produce glial cells yields insights into the neurobiology of Down's syndrome and a number of central nervous system disorders characterized by too many glial cells, according to a recent study by researchers at the Salk Institute for Biological Studies.
Genetics researchers have identified two novel gene locations that raise the risk of type 1 diabetes. As they continue to reveal pieces of the complicated genetic puzzle for this disease, the researchers expect to improve predictive tests and devise preventive strategies.
American researchers have created a prenatal blood test which can be used to determine if an unborn baby has Down's syndrome and the new test is safer for the fetus.
Researchers have discovered two new genes that increase the risk of developing inflammatory bowel disease (IBD) in childhood.
Terms
While we only use edited and approved content for Azthena
answers, it may on occasions provide incorrect responses.
Please confirm any data provided with the related suppliers or
authors. We do not provide medical advice, if you search for
medical information you must always consult a medical
professional before acting on any information provided.
Your questions, but not your email details will be shared with
OpenAI and retained for 30 days in accordance with their
privacy principles.
Please do not ask questions that use sensitive or confidential
information.
Read the full Terms & Conditions.