The FDA has authorized the sale of the Affymetrix CytoScan Dx Assay blood-testing testing system designed to detect chromosomal variations that “may be responsible for a child’s developmental delay or intellectual disability, including Downs Syndrome and DiGeorge Syndrome.”
DiGeorge Syndrome (22q11.2 deletion syndrome), is caused by a defect in chromosome 22, resulting in the poor development of several body systems including heart defects, poor immune system function, a cleft palate, and complications related to low levels of calcium in the blood, as well as certain behavioral disorders.
Down syndrome on the other hand, is caused by mistakes in cell division during development of the human egg, sperm, or embryo, and occurs in 1 out of every 830 births. Over 90% of Down syndrome individuals have three copies of chromosome 21 instead of the normal two in all of their body cells.
The condition is also the leading cause of mild to moderate learning disabilities, developmental delays. Individuals with Downs Syndrome are also recognizable due to specific facial features, and low muscle tone in early infancy. Many individuals also suffer from heart defects, early-onset Alzheimer's disease, gastro-intestinal problems, and other health issues including leukemia.
“This new tool may help in the identification of possible causes of a child’s developmental delay or intellectual disability, allowing health care providers and parents to intervene with appropriate care and support for the child,” said Alberto Gutierrez, Ph.D., director of the Office of In Vitro Diagnostics and Radiological Health in the FDA’s Center for Devices and Radiological Health. “The FDA’s review of the test provides clinical laboratories with information about the expected performance of the device and the quality of the results.”
According to the Agency, the Cyto Scan Dx proved superior to more commonly used methods used to test for abnormaties dealing with fluorescent in situ hybridization (structure and function of chromosomes in a cell) and karotyping (the number and appearance of chromosomes in the nucleus of a eukaryotic cell). However, they stressed that it should “not be used for stand-alone diagnostic purposes, pre-implantation or prenatal testing or screening, population screening, or for the detection of, or screening for acquired or genetic aberrations occurring after birth, such as cancer.”
In addition, results should only be performed only by professions who have been “board-certified” in clinical cytogenetics or molecular genetics,”
For more information contact the FDA at 888-INFO-FDA