Science News
from research organizations

New NIST Reference Material Reinforces Fragile-X Screens

Date:
March 1, 2005
Source:
National Institute Of Standards And Technology
Summary:
A new Standard Reference Material from the National Institute of Standards and Technology (NIST) will help clinical genetics labs improve the accuracy of their diagnostic tests for the most common cause of hereditary mental retardation.
Share:
       
FULL STORY

NIST researcher Kristy Richie analyses DNA samples as part of a project to prepare new "Fragile X" reference materials. (© Robert Rathe)

A new Standard Reference Material from the National Institute of Standards and Technology (NIST) will help clinical genetics labs improve the accuracy of their diagnostic tests for the most common cause of hereditary mental retardation.

“Fragile X Syndrome” is a genetic mutation affecting approximately one in 3,600 males and one in 4,000 to 6,000 females. It has been linked to several physical abnormalities and to intellectual problems ranging from minor learning disabilities to severe mental retardation and autism. The mutation is characterized by an excessive number of repeats of a sequence of three nucleotides (the chemical building blocks of DNA) within a particular gene on the human X chromosome.

Proper diagnosis depends critically on accurate counts of the number of triplet repeats. Individuals with up to 44 repeats are normal; individuals with 55 to 200 repeats fall into the premutation category (unaffected, but the number of repeats can increase in their children, who can then be affected); and those with 200 or more repeats have the full mutation and Fragile X syndrome. In general, the symptoms of the disorder become more severe as the number of repeats increases.

To assist clinical diagnostic and genetic testing laboratories in accurately counting fragile-X repeat sequences, NIST has developed a new reference material that can be used as a check on test procedures and for quality control. SRM 2399, “Fragile X Human DNA Triplet Repeat Standard” consists of nine samples of DNA measured and certified by NIST for triplet repeats ranging from 20 to 118. The triplet repeat standard joins more than 50 reference materials produced by NIST for quality control in clinical testing.


Story Source:

The above post is reprinted from materials provided by National Institute Of Standards And Technology. Note: Materials may be edited for content and length.


Cite This Page:

National Institute Of Standards And Technology. "New NIST Reference Material Reinforces Fragile-X Screens." ScienceDaily. ScienceDaily, 1 March 2005. <www.sciencedaily.com/releases/2005/02/050225105325.htm>.
National Institute Of Standards And Technology. (2005, March 1). New NIST Reference Material Reinforces Fragile-X Screens. ScienceDaily. Retrieved August 2, 2015 from www.sciencedaily.com/releases/2005/02/050225105325.htm
National Institute Of Standards And Technology. "New NIST Reference Material Reinforces Fragile-X Screens." ScienceDaily. www.sciencedaily.com/releases/2005/02/050225105325.htm (accessed August 2, 2015).

Share This Page: