​APHL collaborates with CDC to assure the proficiency of newborn screening laboratory testing. The association works in partnership with the CDC’s Newborn Screening Molecular Biology Branch to support the
Newborn Screening Quality Assurance Program (NSQAP).
NSQAP is a voluntary, non-regulatory program to maintain and enhance the quality of newborn test results at state public health laboratories. It provides services to more than 85 US newborn screening laboratories, 31 manufacturers of diagnostic products and laboratories in 67 countries. NSQAP has served as the reputable source for newborn screening quality assurance services for over 33 years.
NSQAP sends coded specimens to participating laboratories to assess their testing proficiency. If a laboratory makes an error in identification, NSQAP works with the institution to identify the error and improve laboratory practices. The program also publishes quarterly reports to allow laboratories to benchmark practices against their peers.
Newborn Screening Analyte Interference List
The Newborn Screening Analyte Interference List is a compilation of published and observed analyte interferences of newborn screening assays. The list serves as a central, one-stop resource for all known newborn screening assay interferences. Users can both review and add interferences to the list. Categories include:
- Infant Conditions
|
Acid α-glucosidase (GAA) (Pompe Disease) and other LSD's | High hematocrit | False negative |
Butyrylcarnitine (C4) | Mild form of glutamate formiminotransferase deficiency | False positive for SCAD or IBD deficiency |
DNA, PCR | Immunoglobulin G in plasma | Sample failure for CF, SCID and other molecular methods |
DNA, PCR | Elevated hematocrit? | Sample failure for CF, SCID and other molecular methods |
Elevated 17-OHP (?), amino acids, organic acids | Renal immaturity; renal disease | |
Elevated C3 | Hyperbilirubinemia | False positive MMA/PA |
Elevated IRT | Hypoxia | False positive for CF primary screen |
Elevated tyrosine, methionine, galactose, depression of biotinidase enzyme activity | Liver disease | |
GALT activity | G6PD Deficiency | False positive for Galactosemia |
Low T4, elevated TSH | Iodine deficiency | Transient hypothyroidism |
Low T4, elevated TSH, elevated immunoreactive trypsinogen (IRT) | Acute illness | Transient hypothyroidism |
Low T4, normal or low TSH | Central Hypothyroidism | False negative for CH if PTSH is used for screening |
Low T4, normal TSH - followed by elevated TSH | Hypothyroxinemia of preterm birth | Transient hypothyroidism; Mild CH |
Low T4, normal TSH and FT4 | TBG (thyroxine-binding globulin) deficiency | False positive for CH |
Low T4, normal TSH, delayed rise of TSH | Immature hypothalamic-pituitary thyroid axis | False negative for CH |
Lower biotinidase activity levels inversely related to gestational age | Preterm | |
Lower biotinidase activity levels inversely related to gestational age | Preterm | |
Transient elevations of tyrosine | Vitamin C deficiency | Transient neonatal tyrosinemia |
Transient elevations of tyrosine, methionine, and galactose, occasionally other amino acids | Liver enzyme immaturity | |
Varies (most if not all analytes, notably 17-OHP, TSH, IRT) | Baby screened too early after birth | False negative and false positive results |
- Infant Treatment
- Maternal Conditions
- Special Diets
- Specimen in Treatment
How to Nominate an Interference
To nominate an interference, please review the
example and/or the reported analyte interferences above.
- Select "
Nominate an Interference"
- Enter your data. Note that some fields are mandatory. Important: You must enter all your data at one time. It is not possible to save your data and return to it later. Locate your information prior to starting the entry.
- Select Submit to send analyte interference to the QA/QC subcommittee for review.