The U.S. Food and Drug Administration (FDA) has given authorization for marketing the first-ever generic test of diagnosing Fragile X Syndrome (FXS). This syndrome causes developmental delay (genetic) as well as mental disability in newborns.
This new test would be a great help to diagnose Fragile X Syndrome (FXS) along with examining the family records and typical symptoms of Fragile X Syndrome. Moreover, this test would be helpful for adults too who carry the genetic variants of this disease called the FMR1 gene. Wendy Rubinstein is the director of personalized medicine in “In Vitro Diagnostics and Radiological Health” at the FDA’s “Center for Devices and Radiological Health” says;
“This novel diagnostic provides doctors and their patients the first FDA authorized genetic test to aid in diagnosing Fragile X Syndrome, as well as helping parents know their risk of having a child with Fragile X Syndrome. Early diagnosis is key to helping children affected with Fragile X Syndrome through early intervention.”
Centers for Disease Control and Prevention finds that in the US, every 1 in 4,000 men and 1 in 8,000 women are suffering from FXS. It is a genetic condition caused by the FMR1 gene that is a part of the X chromosome.
A small segment of DNA on this gene is repeated multiple times in people who are affected with FXS. This segment is a “CGG trinucleotide” repeat. Sometimes this repetition is customary but a very high repetition represents health problems.
This test kit takes blood samples from suspected patients and checks their repetition of the CGG segment in their FMR1 gene on the X chromosome. Based on the results, it could be determined whether or not these CGG repeats are normal, in-between, pre-mutated or completely mutated.
A complete mutation usually represents Fragile X Syndrome (FXS). This disease causes developmental problems, delays in growth, the problem in learning, behavioral problems, disabilities, and intellectual delays.
If a woman is diagnosed in a transitory number of CGG repeats, she is much likely to give birth to a baby suffering from FXS. Women with Fragile X premutation transfer it to their kids but men with this premutation are only capable of transferring it to their daughters and not sons. People within between or normal CGG repeated segments are considered asymptomatic for Fragile X Syndrome (FXS) and related fragile X disorders.
This test does not just help in diagnosing Fragile X Syndrome but also helps to diagnose the related diseases such as a fragile X-associated tremor/ataxia syndrome. It is a cognitive disorder that affects people over 50 years of age. Another related condition is “fragile X-associated primary ovarian insufficiency”, which affects the regular function of ovaries in women.
This test kit is called “The AmplideX Fragile X Dx and Carrier Screen Kit” and it is not to be used for fetal testing. The information on this test was received by FDA through the de novo classification process. It is a regulatory mechanism to evaluate low- to moderate-risk new medical devices.
FDA has analyzed the data obtained from three clinical sites to estimate its accuracy. The results depicted that this new test is 95% accurate in diagnosing Fragile X Syndrome (FXS).