Posted Date
Effective Date
Update Type Test Methodology Changed
Order Code SNPM1



Chromosomal Microarray Analysis, Blood

Order Code:                  SNPM1

New Order Code:          GDCMA

New Fee Code:             DA175 (CPT 81229, G0452-26)


The MMGL Molecular Genetics Laboratory has changed their Chromosomal Microarray (CMA) assay for germline/constitutional genetic disorders from the Illumina CytoSNP-850K array to the Illumina Global Diversity Array With Cytogenetics (GDAC) content effective June 20, 2023.  The GDAC contains 1.8M markers, which is approximately a million more markers than the CytoSNP-850K array. The improvements incorporated in this array aid in the detection of copy number variants (CNVs) associated with Mendelian conditions or syndromes, dysmorphic features, congenital anomalies, developmental delays, cognitive impairments, and autism spectrum disorders. The array also has enhanced supplemental exonic coverage of cytogenetic-relevant genes.


The GDAC backbone content is based on the Illumina Global Diversity Array (GDA). The GDA was chosen by the National Institutes of Health for the All of Us research program.