CFTR and cystic fibrosis: The CDC’s Newborn Screening Quality Assurance Program (NSQAP) provides DBS proficiency testing to United States and international laboratories for both IRT (N = 215 laboratories, quarter 1 of 2016) and CFTR mutation detection (N = 68 laboratories, quarter 1 of 2016).21,22 The NSQAP’s CF DNA DBS repository, made from CF patient and family blood samples, contains a wide variety of CFTR mutations including the 23 recommended by ACMG as well as 47 additional mutations.