The laboratory test from Affymetrix detects variations in patients' chromosomes that are linked to Down syndrome, DiGeorge syndrome and other developmental disorders.
About 2 to 3 per cent of US children have some sort of intellectual disability, according to the National Institutes of Health.
The test, known as the CytoScan Dx Assay, is designed to help doctors diagnose children's' disabilities earlier and get them appropriate care and support. It is not intended for prenatal screening or for predicting other genetically acquired diseases and conditions, such as cancer.
The mandatory screening program, begun a half-century ago, is considered one of the nation's most successful public health programs.
The FDA said it approved the new test based on studies showing it accurately analyses a patient's entire genome and accurately spot variations associated with intellectual disabilities.
Affymetrix Inc. Is based in Santa Clara, California.