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:12/7/2016)... to a new market research report "Emotion Detection and Recognition Market by Technology ... End User, And Region - Global Forecast to 2021", published by MarketsandMarkets, the ... USD 36.07 Billion by 2021, at a Compound Annual Growth Rate (CAGR) of ... ... MarketsandMarkets Logo ...
(Date:12/7/2016)... 2016   Avanade is helping Williams Martini ... in history, exploit biometric data in order to critically ... the competitive edge against their rivals after their impressive, ... Avanade has worked with Williams during the 2016 season ... (heart rate, breathing rate, temperature and peak acceleration) for ...
(Date:12/6/2016)... Dec. 6, 2016  Zimmer Biomet Holdings, Inc. (NYSE and ... an offering of €500.0 million principal amount of its 1.414% ... of its 2.425% senior unsecured notes due 2026. ... on December 13, 2016, subject to the satisfaction of customary closing ... The Company intends to use ...
Breaking Biology News(10 mins):
(Date:1/12/2017)... (PRWEB) , ... January 12, ... ... disposable devices with short response times capable of performing routine electrochemical biosensing ... disposable screen-printed electrodes provide fast, sensitive detection and quantification of various analytes ...
(Date:1/12/2017)... 12, 2017   Protein Sciences Corporation , ... Flublok Influenza Vaccine ®, announced today that ... good safety results and induced strong neutralizing antibodies ... product is expected to advance into human clinical ... the Institute of Technology in Immunobiologicals of the ...
(Date:1/11/2017)... ... January 11, 2017 , ... Phase ... show early promise of the investigational anti-cancer agent tucatinib (formerly ONT-380) against HER2+ ... treatment regimens. Twenty-seven percent of these heavily pretreated patients saw clinical benefit from ...
(Date:1/11/2017)... -- Brian Mehling, M.D., world-renowned stem cell researcher, board-certified orthopedic ... will be attending the 47th Annual World Economic Forum ... 17-20, 2017. This will be Dr. Mehling,s fifth year ... this year,s forum is Responsive and Responsible Leadership; over ... for fostering greater social inclusion and human development. One-third ...
Breaking Biology Technology: