Navigation Links
A nucleotide change could initiate fragile X syndrome
Date:9/1/2014

Researchers reveal how the alteration of a single nucleotidethe basic building block of DNAcould initiate fragile X syndrome, the most common inherited form of intellectual disability. The study appears in The Journal of Cell Biology.

Fragile X syndrome is caused by a defect in a gene on the X chromosome called fragile X mental retardation 1 (FMR1). Around 1 in 230 women and 1 in 360 men carry a so-called premutation, in which a series of DNA repeats at one end of the FMR1 gene is slightly longer than normal. These repeats are prone to even further expansion when FMR1 is passed from mother to child, causing the gene to switch off and stop producing a protein that is important for some cognitive functions.

A group of researchers from Albert Einstein College of Medicine of Yeshiva University in New York previously found that a certain site that initiates DNA replication, located near to the FMR1 gene, is inactivated in fragile X embryonic stem cells. This inactivation changes the way that the FMR1 gene is copied during cell division, which could pose problems that lead to expansion of the DNA repeats within the gene.

Intriguingly, a specific alteration in the DNA sequence near the FMR1 genea "single-nucleotide polymorphism" or SNP has been linked to an increased risk of repeat expansion in some premutation carriers. These researchers discovered that this SNP overlaps with the inactive replication origin in fragile X embryonic stem cells.

Nucleotides in DNA include one of four bases (cytosine, thymine, adenine, or guanine). The researchers found that normal embryonic stem cells had a thymine base at the SNP site and an active replication origin. Fragile X cells, in contrast, had a cytosine base and an inactive origin. The researchers also derived embryonic stem cells from mothers carrying the fragile X premutation. These cells had a thymine base and a normal replication pattern and, accordingly, showed no tendency to expand their repeat numbers over time.

The findings show that the substitution of cytosine for thymine might inactivate the DNA replication origin when the FMR1 gene is passed from mother to child, increasing the risk of DNA repeat expansions that can lead to fragile X syndrome.


'/>"/>

Contact: Rita Sullivan King
news@rupress.org
212-327-8603
Rockefeller University Press
Source:Eurekalert  

Related biology news :

1. Oligonucleotide Delivery: Biology, Engineering and Development Conference
2. Industry group release testing recommendations for oligonucleotide-based therapeutics
3. Splice-switching oligonucleotide therapeutics is new method for editing gene transcript
4. Holding a mirror to brain changes in autism
5. New study will help protect vulnerable birds from impacts of climate change
6. UNH researchers find African farmers need better climate change data to improve farming practices
7. Fielding questions about climate change
8. Glacier-fed river systems threatened by climate change
9. How old are these rocks, how were they made, and how long ago did these geologic changes happen?
10. Energy requirements make Antarctic fur seal pups vulnerable to climate change
11. Why spring is blooming marvelous (and climate change makes it earlier)
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
A nucleotide change could initiate fragile X syndrome
(Date:1/18/2016)... Jan. 18, 2016  Extenua Inc., a pioneering ... the use and access of ubiquitous on-premise and ... with American Cyber.  ... leading transformational C4ISR and Cyber initiatives in support ... latest proven technology solutions," said Steve Visconti ...
(Date:1/13/2016)... --> --> ... report titled - Biometric Sensors Market - Global Industry Analysis, ... to the report, the global biometric sensors market was valued at ... US$1,625.8 mn by 2023, expanding at a CAGR of ... the biometric sensors market is expected to reach 1,799.6 ...
(Date:1/11/2016)... JOSE, Calif. , Jan. 11, 2016 ... of human interface solutions, today announced that its ClearPad ... driver integration (TDDI) products won two separate categories in ... Best Mobile Innovator and Best Technology Breakthrough. The Synaptics ... system cost, a simplified supply chain, thinner devices, brighter ...
Breaking Biology News(10 mins):
(Date:2/11/2016)... ... February 11, 2016 , ... Reichert Technologies, which has ... to pursue the highest level of accuracy and quality with the addition of ... the AR5 Refractometer. Accurate, reliable and tough enough for the most demanding ...
(Date:2/11/2016)... ... , ... Global Stem Cells Group, has announced ... new facility will provide advanced protocols and state-of-the-art techniques in cellular medicine, focusing ... The new GSCG clinic is headed by four prominent Ecuadorian physicians, including Pablo ...
(Date:2/10/2016)... -- Early-career researchers from Indonesia ... Uganda and Yemen ...   Indonesia , Nepal , ... Yemen are being honored for their accomplishments in nutrition, ... for mentoring young women scientists who are pursuing careers in agriculture, biology ...
(Date:2/10/2016)... , Feb. 10, 2016 NX Prenatal ... its proprietary NeXosome® technology for early warning of ... its most recent study by Dr. Thomas ... the Society for Maternal Fetal Medicine,s (SMFM) annual meeting ... 1-6 th , 2016.  The presentation reported initial ...
Breaking Biology Technology: