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.

Study provides insight into earliest stages of some cancers

A novel technique that enables scientists to measure and document tumor-inducing changes in DNA is providing new insight into the earliest events involved in the formation of leukemias, lymphomas and sarcomas, and could potentially lead to the discovery of ways to stop those events.

30 Sep 2011

Prototype drug shows promise against chronic lymphocytic leukemia

Pre-clinical research has generated some very promising findings about a prototype drug for the treatment of chronic lymphocytic leukemia.

29 Sep 2011

X-chromosome related microRNA may impact immunity and cancer

As anyone familiar with the phrase 'man-flu' will know women consider themselves to be the more robust side of the species when it comes to health and illness. Now new research, published in BioEssays, seems to support the idea. The research focuses on the role of MicroRNAs encoded on the X chromosome to explain why women have stronger immune systems to men and are less likely to develop cancer.

28 Sep 2011

Afraxis to participate in NIH's Therapeutics for Rare and Neglected Disease Program

Afraxis, a San Diego-based biotechnology company developing drugs to treat rare genetic diseases through the modulation of p21-activated kinase (PAK), announced today that it has been selected to participate in the National Institutes of Health's (NIH) Therapeutics for Rare and Neglected Disease (TRND) Program.

27 Sep 2011

Duplication of RPS6KA3 gene produces limited family intellectual disability

The financial contributions made some years ago by individuals and public administration bodies in the telemarathon solidarity events on the Basque Public Broadcasting Corporation (EiTB) and subsequently channelled through the Basque Foundation for Health Innovation and Research (BIOEF), has resulted in undertaking successful innovative research at the Cruces Hospital near Bilbao in the Basque province of Bizkaia, describing a new syndrome of limited family intellectual disability.

26 Sep 2011

Researchers analyse effects of BPA in an in-vitro culture of ovaries

Researchers at Universitat Aut-noma de Barcelona, in collaboration with the Vall d'Hebron Hospital Fetal Tissue Bank, the Department of Gynaecology and the Research Unit of Paediatric Endocrinology, analysed the effects of Bisphenol A (BPA), a polymer widely used to manufacture plastics, in an in vitro culture of ovaries.

22 Sep 2011

Families help identify new gene for motor neuron disease

Families suffering from a history of motor neuron disease have helped an international scientific team locate a new gene linked to the incurable disease.

22 Sep 2011

Researchers identify common genetic mutation for ALS, frontotemporal dementia

Frontotemporal dementia and amyotrophic lateral sclerosis, also known as Lou Gehrig's disease -- two fatal neurodegenerative disease with distinct but sometimes overlapping symptoms -- are triggered by a common mutation in many cases, according to researchers who say they have identified the mutated gene.

22 Sep 2011

Scientists discover new genetic mutation for amyotrophic lateral sclerosis

A team led by scientists from Johns Hopkins and the National Institutes of Health has discovered a new genetic mutation for amyotrophic lateral sclerosis (ALS) and a related disease called frontotemporal dementia (FTD) that appears to account for more than a third of all inherited cases of these diseases.

22 Sep 2011

Chromatin, Dow AgroSciences achieve first milestone in research collaboration

Chromatin Inc. announced today that they have reached the first milestone in their research collaboration with Dow AgroSciences LLC, a wholly owned subsidiary of The Dow Chemical Company. This collaboration is focused on developing a novel combination of Chromatin's Mini-Chromosomes with Dow AgroSciences' EXZACT Precision Technology.

12 Sep 2011

Common genetic variant may predispose people to acute dissections

Richard Holbrooke, John Ritter, Lucille Ball, Jonathan Larson and Great Britain's King George II were all taken by the same silent killer: an acute aortic dissection. Now, scientists led by researchers at The University of Texas Health Science Center at Houston and Baylor College of Medicine have found an association with a common genetic variant in the population that predisposes people to acute dissections and can approximately double a person's chances of having the disease.

12 Sep 2011

Study: No big shift toward higher fatal heart attack rates after menopause in women

Contradicting the long-held medical belief that the risk of cardiovascular death for women spikes sharply after menopause, new research from Johns Hopkins suggests instead that heart disease mortality rates in women progress at a constant rate as they age.

6 Sep 2011

Chromatin might have another life as direct signaling molecule

Chromatin - the intertwined histone proteins and DNA that make up chromosomes - constantly receives messages that pour in from a cell's intricate signaling networks: Turn that gene on. Stifle that one. But chromatin also talks back, scientists at The University of Texas MD Anderson Cancer Center report today in the journal Cell, issuing orders affecting a protein that has nothing to do with chromatin's central role in gene transcription - the first step in protein formation.

2 Sep 2011

Scientists discover genetic cause of extreme thinness

Scientists have discovered a genetic cause of extreme thinness for the first time, in a study published today in the journal Nature.

2 Sep 2011

Stanford method identifies essential regions of Caulobacter's genome

A team at the Stanford University School of Medicine has cataloged, down to the letter, exactly what parts of the genetic code are essential for survival in one bacterial species, Caulobacter crescentus.

31 Aug 2011

FDA approves Abbott's Vysis ALK FISH test for NSCLC therapy selection

Abbott today announced it has received approval from the U.S. Food and Drug Administration (FDA) for a new molecular diagnostic test designed to detect rearrangements of the anaplastic lymphoma kinase (ALK) gene in non-small-cell lung cancer.

29 Aug 2011

Protein that allows Ebola virus to attack cells discovered

A U.S. research team has discovered a protein called Niemann-Pick C1 (NPC1), which they found was responsible for allowing Ebola virus to enter and replicate within cells.

26 Aug 2011

Researchers reveal new gene associated with osteoarthritis

Researchers have today revealed a new gene associated with osteoarthritis. This is only the third gene to be identified for this painful and debilitating disease that affects more than 40 per cent of people aged more than 70 years.

26 Aug 2011

Researchers discover NPC1 protein as crucial for Ebola virus to enter host cells

Although outbreaks are rare, Ebola virus, the cause of Ebola hemorrhagic fever (EHF), is one of the deadliest known viruses affecting humans. According to the World Health Organization (WHO), approximately 1,850 EHF cases with more than 1,200 deaths have been documented since the virus was identified in 1976.

25 Aug 2011

Scientists identify molecular pathway that plays a key role in stress-related DNA damage

Working closely with a team of researchers from Duke University, scientists from the Florida campus of The Scripps Research Institute have helped identify a molecular pathway that plays a key role in stress-related damage to the genome, the entirety of an organism's hereditary information.

23 Aug 2011