Posted Date
Effective Date
Update Type Test Methodology Changed
CPT Code 81331
Order Code PWSMP



Prader-Willi / Angelman Syndrome Analysis

Order Code:                  PWSMP

Fee Code:                     DA030


Effective March 29, 2022, the test name for this assay was updated in our Laboratory Information System from Prader-Willi/Angelman by PCR to Prader-Willi Angelman Analysis. The test methodology has changed to MS- MLPA (Methylation Specific Multiplex Ligation-dependent Probe Amplification) to determine the methylation status and the copy number at imprinted loci in 15q11.2 (5’ SNRPN) from bisulfite conversion and PCR amplification to detect abnormal methylation patterns in the SNRPN gene. This change in assay methodology to MS-MLPA will allow the detection of copy number gains in addition to losses and hyper-methylation and hypo-methylation in the targeted 15q11.2 region.