NEW YORK (GenomeWeb News) – Quest Diagnostics today said that New York has given the go-ahead for the company's test for Fragile X Syndrome, making it now available in all 50 states.
The New York State Department of Health has approved Quest's XSense Fragile X with Reflex to identify female carriers and other patients with genetic abnormalities that can result in the disease, which is the leading cause of inherited mental retardation and most common known single-gene cause of autism, according to Quest.
The standard widely used lab-testing method for Fragile X Syndrome is Southern Blot DNA analysis, which can take several days to weeks for results. In a statement, Quest said that Southern Blot "has hampered the lab industry's ability to widely provide Fragile X testing."
The XSense test bypasses the need for Southern Blot DNA analysis in 99 percent of cases, and test results are available in one week for most patients, the company added.
The XSense test identifies abnormalities in the fragile X mental retardation 1 gene residing on the X chromosome by using triplet-primed polymerase chain reaction by capillary electrolysis to assess the number of times a certain DNA pattern called CGG repeats. The number of CGG occurrences determines whether a person has a premutation and is a carrier or has a full mutation and has Fragile X Syndrome.
Quest offers XSense "in alignment with current guidelines of Fragile X Syndrome testing," the company said.
The National Fragile X Foundation estimates that one in 260 women carry the gene for Fragile X Syndrome, but Quest researchers and others suggest the figure may be higher.