Chromosome X News and Research

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The X chromosome is one of the two sex chromosomes in humans (the other is the Y chromosome). The sex chromosomes form one of the 23 pairs of human chromosomes in each cell. The X chromosome spans about 155 million base pairs (the building blocks of DNA) and represents approximately 5 percent of the total DNA in cells.

Each person normally has one pair of sex chromosomes in each cell. Females have two X chromosomes, while males have one X and one Y chromosome. Early in embryonic development in females, one of the two X chromosomes is randomly and permanently inactivated in somatic cells (cells other than egg and sperm cells). This phenomenon is called X-inactivation or Lyonization. X-inactivation ensures that females, like males, have one functional copy of the X chromosome in each body cell. Because X-inactivation is random, in normal females the X chromosome inherited from the mother is active in some cells, and the X chromosome inherited from the father is active in other cells.

Some genes on the X chromosome escape X-inactivation. These genes are located at the tip of the short (p) arm of the X chromosome in an area known as the pseudoautosomal region. Although many genes are unique to the X or Y chromosome, genes in the pseudoautosomal region are present on both chromosomes. As a result, men and women each have two functional copies of these genes. Many genes in the pseudoautosomal region are essential for normal development.

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. The X chromosome likely contains between 900 and 1,400 genes.

Genes on the X chromosome are among the estimated 20,000 to 25,000 total genes in the human genome.

IMF to stage presentation on multiple myeloma at ASH annual meeting

The International Myeloma Foundation (IMF)—supporting research and providing education, advocacy and support for myeloma patients, families, researchers and physicians—today said presentations at the annual meeting of the American Society of Hematology (ASH) will cover all stages of multiple myeloma, a major milestone in treating this and related cancers.

4 Dec 2009

Researchers discover mechanism that explains how chromosomal translocations are not random

Researchers at the UC San Diego School of Medicine have pinpointed a mechanism that may help explain how chromosomal translocations - the supposedly random shuffling of large chunks of DNA that frequently lead to cancer - aren't so random after all. They have developed a model of such chromosomal mix-ups in prostate cancer which indicates that the male sex hormone (androgen) receptor unexpectedly plays a key role in driving specific translocations in the development of cancer.

4 Dec 2009

More than 80 abstracts highlighting Bristol-Myers Squibb's oncology compound to be presented

Bristol-Myers Squibb Company today announced that more than 80 abstracts highlighting compounds from the company’s oncology portfolio will be presented at the 51st Annual Meeting of the American Society of Hematology (ASH) to be held December 5-8 in New Orleans.

3 Dec 2009

New data demonstrating the strength of Novartis' hematology portfolio to be presented

Novartis announced today that new data, including a late-breaking presentation on Tasigna® (nilotinib) 200 mg capsules in a form of chronic myeloid leukemia, demonstrate the strength of the company's hematology portfolio in advancing the care of patients.

2 Dec 2009

Sperm genes may have a detrimental effect on longevity, says new study

Researchers in Japan have found that female mice produced by using genetic material from two mothers but no father live significantly longer than mice with the normal mix of maternal and paternal genes. Their findings provide the first evidence that sperm genes may have a detrimental effect on lifespan in mammals.

1 Dec 2009

Developmental and behavior problems in individuals with autism associated DNA imbalance characterized

Researchers at Signature Genomic Laboratories, which performs diagnostic genetic testing of chromosome abnormalities in individuals with unexplained physical and developmental disabilities, including autism, recently characterized a broad spectrum of developmental and behavior problems in individuals with a DNA imbalance that has been associated with autism.

24 Nov 2009

NCCN Guidelines adds ofatumumab and romidepsin as therapy options for CLL

Two recent FDA approvals have prompted the National Comprehensive Cancer Network (NCCN) to update the NCCN Clinical Practice Guidelines in Oncology(TM) for Non-Hodgkin's Lymphomas to include ofatumumab (Azerra(TM), GlaxoSmithKline) and romidepsin (Istodax(R), Gloucester Pharmaceuticals) as treatment options for select patients with two types of Non-Hodgkin's Lymphomas.

24 Nov 2009

Gene deletion can increase common complication of bone marrow transplants

A commonly inherited gene deletion can increase the likelihood of immune complications following bone marrow transplantation, an international team of researchers reports in the November 22 advance online issue of Nature Genetics.

23 Nov 2009

Microarray analysis can identify chromosome abnormalities in children with Pitt-Hopkins syndrome

Researchers at Signature Genomic Laboratories, which performs diagnostic genetic testing of chromosome abnormalities in individuals with unexplained physical and developmental disabilities, recently showed that microarray analysis can identify small DNA alterations in individuals with Pitt-Hopkins syndrome, a rare and poorly characterized genetic disorder.

19 Nov 2009

Possible new approach to slow the progression of cognitive decline in Down's syndrome

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.

19 Nov 2009

Asuragen enters into an exclusive agreement with Life Technologies

Asuragen, Inc. announced today that it has entered into an exclusive agreement with Life Technologies Corporation to develop and distribute worldwide an in-vitro diagnostic test intended to aid clinicians in the monitoring and treatment of individuals afflicted with chronic myeloid leukemia (CML).

18 Nov 2009

Cytoskeleton plays a critical role to bring chromosome pairs together: Study

Meiosis - the pairing and recombination of chromosomes, followed by segregation of half to each egg or sperm cell - is a major crossroads in all organisms reproducing sexually. Yet, how the cell precisely choreographs these chromosomal interactions is a long-standing question.

16 Nov 2009

Research team identifies five new gene regions that raise the risk of childhood-onset IBD

In the largest, most comprehensive genetic analysis of childhood-onset inflammatory bowel disease (IBD), an international research team has identified five new gene regions, including one involved in a biological pathway that helps drive the painful inflammation of the digestive tract that characterizes the disease.

16 Nov 2009

Co-founders of Signature Genomics recognized with Inland Northwest Catalyst Award

Signature Genomics, which performs diagnostic genetic testing of chromosome abnormalities in individuals with unexplained mental retardation and/or birth defects, today announced company co-founders Dr. Lisa G. Shaffer, Ph.D., and Dr. Bassem A. Bejjani, M.D. have received the 2009 Inland Northwest Catalyst Award for Innovators of the Year.

12 Nov 2009

U.S. Patent and Trademark Office awards new patent for Ryogen

Ryogen LLC, a genomic start-up company, has been awarded a new patent titled “Isolated Genomic Polynucleotide Fragments from Chromosome 7”.

12 Nov 2009

Activating TAp63 protein, a viable anti-cancer strategy

Oncologists have had their hands tied because more than half of all human cancers have mutations that disable a protein called p53. As a critical anti-cancer watchdog, p53 masterminds several cancer-fighting operations within cells. When cells lose p53, tumors grow aggressively and often cannot be treated.

10 Nov 2009

Chinese SFDA approves China Medical Technologies' Leukemia BCR/ABL fusion gene detection FISH Probe

China Medical Technologies, Inc., a leading China-based medical device company that develops, manufactures and markets advanced in-vitro diagnostic products, today announced that the Company has received approval for its Leukemia BCR/ABL fusion gene detection FISH Probe (the "Leukemia BCR/ABL FISH Probe") from the State Food and Drug Administration of China (the "SFDA").

9 Nov 2009

Cellular mechanisms that may impact immune functions in the elderly discovered

Investigators discover cellular mechanisms that may impact the decline of both innate and adaptive immune functions that increase the susceptibility to various infectious agents, cancer and diseases in the elderly say experts at the annual meeting of the American College of Allergy, Asthma and Immunology (ACAAI) in Miami Beach, Fla.

9 Nov 2009

Researchers find compound that reverses type 1 myotonic dystrophy

A compound already used to treat pneumonia could become a new therapy for an inherited muscular wasting disease, according to researchers at the University of Oregon and the University of Rochester School of Medicine and Dentistry in New York.

7 Nov 2009

Autism Consortium holds its fourth annual symposium to update on autism

The Autism Consortium, an innovative collaboration of researchers, clinicians, funders and families dedicated to catalyzing research and enhancing clinical care for autism spectrum disorders (ASDs), held its fourth annual symposium on October 28th, 2009, at Harvard Medical School in Boston.

6 Nov 2009