FDA Clears First-of-Its-kind Postnatal Test for Developmental Disabilities

The US Food and Drug Administration (FDA) has recently cleared a new postnatal blood test to help diagnose children’s genetic-based developmental disabilities more comprehensively by enabling a high-resolution genome-wide analysis of genetic aberrations.

Affymetrix (Santa Clara, CA, USA) has received 510(k) clearance to market its "CytoScan Dx Assay", which improves diagnostic capability as the high-resolution analysis can reveal small aberrations not readily detected with traditional technologies. Many disabilities are associated with chromosomal variations; CytoScan Dx can detect chromosomal variations that may be responsible for a child’s developmental delay or intellectual disability. The assay is intended for the postnatal detection of DNA copy number variants (CNV) in patients referred for chromosomal testing. Based on a blood sample, the test can analyze the entire genome at once and detect large and small chromosomal changes.

“This new tool may help in the identification of possible causes of a child’s developmental delay or intellectual disability,” said Alberto Gutierrez, PhD, director of the FDA's Office of In Vitro Diagnostics 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.” The review included an analytical evaluation of the test’s ability to accurately detect numerous chromosomal variations of different types, sizes, and genome locations when compared to several analytically validated test methods. CytoScan Dx could analyze a patient’s entire genome and adequately detect chromosome variations in regions of the genome associated with intellectual and developmental disabilities. The review also included a study comparing performance of CytoScan Dx to test for variations associated with a given developmental delay or intellectual disability—results from 960 blood specimens showed that CytoScan Dx had improved detection ability over commonly used tests, including karyotyping and FISH chromosomal tests.

“This clearance is first-of-its-kind, and represents a leap forward in molecular genetic testing. CytoScan Dx Assay is the first FDA-cleared test that analyzes the whole genome in a single assay at unprecedented resolution, which significantly improves diagnostic capability. Developing and clearing this assay establish Affymetrix as a leader in advancing molecular diagnostics by bringing high quality genomic tools into routine application in the clinic,” said Frank Witney, CEO and President of Affymetrix.

"We are pleased to have been selected by Affymetrix to be part of the clinical trial for CytoScan Dx Assay and found the performance data of this assay very impressive. [...] This assay represents the best option for accelerating an accurate diagnosis," said Alka Chaubey, PhD, Director of the Greenwood Genetic Center's Cytogenetics Laboratory.

CytoScan Dx results should only be used in conjunction with other relevant clinical and diagnostic methods (including confirmation by alternative tests), and consistent with professional standards of practice and interpretation in clinical genetics.

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