Commercial laboratories offering cell free DNA for fetal prenatal screening are offering microdeletion testing. Is this valid? Microdeletions are varied and include 22q and 15q syndromes. In this session, we will review the pathophysiology of microdeletions and review 22q and 15q conditions. What does the SMFM have to say about cell free DNA screening for these conditions? How is Angelman syndrome related to Prader –Willi condition? Let’s cover this now.