Constitutional chromosomal microarray analysis | CMA
Test Details | Affymetrix CytoScan HD assay with genomic DNA extraction to detect small gains and losses across the entire genome. A genomic imbalance is ALWAYS REPORTED when deletions are greater than 200 kb and duplications are greater than 500 kb, unless they represent a region clearly associated with benign copy number polymorphism in multiple independent studies. Regions of LCSH are reported when they are greater than 10 Mb. Deletions smaller than 200 kb and duplications smaller than 500 kb are NOT REPORTED, unless they involve regions of the genome with clear clinical significance. |
Methodology | Chromosomal microarray analysis |
Performed | Monday – Friday |
Turnaround | 21 – 28 days |
Specimen Requirements | Peripheral blood (PB), fibroblasts |
Sample Collection | PB: 2 tubes of peripheral blood (EDTA and NaHeparin). Fibroblasts: 2-T25 flasks of cultured fibroblasts; or fresh fibroblast biopsy. Flasks should be confluent or nearly confluent prior to testing; transport with adequate media; fresh tissue will require cell culture prior to CMA study |
Storage/Transport Conditions | Room temperature |
Unacceptable Conditions | Frozen specimens, clotted or hemolyzed specimens, inappropriate tube type, paraffin samples |
Special Instructions | If patient has had a recent blood transfusion with leukocytes, it is recommended to wait at least 2 weeks after the transfusion date (packed RBC ok) |
CPT Code(s) | 81229×1; Optional reflex karyotype available if microarray is normal: if requested add CPT codes 88230, 88291, 88262 and 88280 (all x 1) |