The US Food and Drug Administration (FDA) has granted marketing authorisation to Asuragen for its AmplideX Fragile X Dx and Carrier Screen Kit to help identify Fragile X Syndrome, a genetic condition that leads to inherited developmental delay and intellectual disability.
The first-of-its-kind test is for use alongside an evaluation of a patient’s family history and symptoms and clinical signs of FXS.
The diagnostic can also be used in adults who may carry genetic alterations in the gene-related with FXS, FMR1 gene.
FDA’s Center for Devices and Radiological Health’s Office of In Vitro Diagnostics and Radiological Health director of personalised medicine Wendy Rubinstein said: “This novel diagnostic provides doctors and their patients the first FDA authorised 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.”
Nearly one in 4,000 males and one in 8,000 females in the US have FXS, according to Centers for Disease Control and Prevention. This condition is a genetic disorder caused by changes in the FMR1 gene located on the X chromosome.
In individuals with Fragile X Syndrome, a DNA segment in the gene CGG trinucleotide repeat is reproduced in excess on the X chromosome. Although some repetition of CCG repeats is considered normal, the high number of repeats may point to potential health risks.
AmplideX Fragile X Dx and Carrier Screen Kit measures the number of repeats of the CGG segment in the FMR1 gene using blood samples from a patient and detects whether CGG repeats in the patient is considered normal, intermediate, premutation or full mutation.
Full mutation in patients typically indicates FXS. Developmental delays, learning disabilities, social and behavioural issues, intellectual disabilities and autism spectrum disorder are the conditions associated with FXS.
Using de nova classification process, the FDA evaluated data from specimens collected at three clinical sites to assess the accuracy of the test. The data indicated that the diagnostic accuracy of the test is greater than 95%.
Besides helping in the diagnosis of FXS and for carrier testing, the test can be used in the diagnosis of fragile X-associated disorders, including fragile X-associated tremor / ataxia syndrome, a movement and cognitive disorder, and fragile X-associated primary ovarian insufficiency, a condition with reduced function of the ovaries.