Newborn Screening Flashcards
Components of a newborn screen (6)
- Education of professionals and parents
- Screening (specimen collection, submission, and testing)
- Follow-up of abnormal and unsatisfactory test results
- Confirmatory testing and diagnosis
- Medical management and periodic outcome evaluation
- System quality assurance: Including program evaluation, validity of testing systems, efficiency of follow-up and intervention, and assessments of long-term benefits to individuals, families, and society.
Criteria for Inclusion on NBS Panel (9)
- Accurate screening test.
- Significant life-challenging risk of morbidity if the disorder is untreated in newborns.
- Natural history of the disease understood
- The disorder must be treatable and require early treatment.
- Total costs of the system from diagnosis to follow-up must be reasonably priced
- Resources for and access to confirmatory testing, treatment and counseling.
- Significant prevalence of the disorder
- Positive health benefits must outweigh risks and burdens
- Regular review of scientific and medical rationale
Categories of diseases on current NYS panel (8)
- Inborn Errors of Metabolism
a. Aminoacidopathies
b. Fatty Acid Oxidation Defects
c. Organic Acidemias
d. Urea Cycle Defects
e. Other Inborn Errors of Metabolism - Hemoglobinopathies disorders – SS, SC and trait
- Endocrine disorders
a. CAH
b. CH - Cystic Fibrosis
- HIV
- Krabbe disease
- SCID
- Pompe
Pompe Disease Overview (4)
- Rare 1:40,000
- Inherited, fatal disorders if complete deficiency
- Presents in early infancy with hypotonia
- Cannot breakdown glycogen d/t lack of GAA – excessive amounts of lysosomal glycogen accumulates in the body
a. Heart
b. Skeletal
Pompe Disease Presentation (8)
(Early Infancy Presentation)
a. poor feeding
b. Poor weight gain
c. Poor tone “floppiness”
d. Head lag
e. Respiratory difficulties
f. Enlarged heart
g. Enlarged tongue
h. Most die within first year of life – cardiac/respiratory complications
Steps in newborn screen process (8)
Step 1: Sample Collection 24 hours post eating
Step 2: Sample Processing
Step 3: Testing
a. Tandem MS
b. ELISA
c. Bioassay
Step 4: Reporting of Positive Results
Step 5: Contacting family
Step 6: Confirmatory testing and treatment
Step 7: Reporting diagnosis back to state
Step 8: Data collection
Timing in Specimen Collection (8)
- The AAP recommends that the specimen be collected after the newborn is at least 24 hours old
- A specimen collected before 24 hours of age can be used for some disorders BUT is not reliable for AA disorders, CF, hypothyroidism, or Urea Cycle disorders.
- 2nd day of life screening is acceptable for ALL
- Never discharge a newborn without a screening (unless refusal)
- If discharged or screened before 24 hours of life- a repeat test should be done on when the baby is between 24-120 hours of age. (day 2-5)
- Premature and Sick infants – special circumstances- should have a specimen drawn before a blood transfusion or TPN initiated regardless of age – These will be repeated as per NICU protocol (2nd specimen at 48-72 hours / 3rd at discharge or 28 days whichever comes first)
- Send out within 24 hours of collection – IDEAL!
- Special circumstances – international adoption/military – refer to country and repeat is recommended unless a military base run program
Tandem MS (7)
- Detects molecules by measuring the weight (mass)
- Results displayed in the form of a mass spectrum-a graph of how much is present
- A single NBS contains thousands of molecules
- When alcohol is added to the “dried blood spot” several hundred molecules are pulled out and can be studied by TMS
- Very quick and accurate
- Measures the amount of AA in the blood and tells us whether or not there is too much of the compound in the blood-excess = poison
- Good for NBS because it can measure many different molecules in a single test
Bioassay
(e. g. Galactosemia, Biotinidase deficiency, Krabbe disease)
* Colorimetric method to determine presence of absence of enzymatic activity
Consent for Screening (3)
- AAP recommends that parents be informed that screening tests are being done and that parental permission should be obtained, most states continue with the newborn screening program as an “opt out” test and therefore no permission is required before the testing is done.
- In order for parents to opt out, they must know in advance that a test is being performed and then must proactively opt out of the program if they do not want their baby screened in the nursery.
- What happens to the rest of the dried “blood spot?”
a. In NYS the blood is kept and de-identified for use in research or for diagnostic purposes for the child involved
b. In NYS the residual blood spot retention is 27 years
c. Storage is secure and access controlled
d. You can deny this as a parent by calling your State and opting out.
Knowledge gap on screening (8)
- Obstetricians don’t always inform mothers of test
- Nursing staff refer to testing as “the PKU”
- Poor understanding of timing and collection issues
- Pediatricians unfamiliar with disorders on panel
- “No news is good news” attitude versus checking results
- Providers unfamiliar with who to consult
- Hospital follow-up personnel may not be medically trained
- Little support for parents if infant is diagnosed with rare disease
False positives
Conclusions: False-positive screening results may affect parental stress and the parent-child relationship. Improved communication with parents regarding the need for repeat screening tests may reduce the negative impact of false-positive results.
False negatives
Timing of specimen collection affects results.
*Delays and lack of knowledge by those performing the test
Summary role of PNP
- Newborn screening is an incredibly powerful public health tool
- Diseases that are screened for include inborn errors of metabolism, infectious disease (HIV), endocrine disorders, hemoglobinopathies and channelopathies (CF) and the list is growing!
- The testing is state dependent and There is a lack of state uniformity regarding the recommended panel of diseases – SO know your state!
- False positive results are a significant source of psychological stress in families
- We need to be advocates for NBS
- Be aware of new technologies – DNA sequencing/fetal DNA
- NBS saves lives! SO PLEASE FOLLOW UP THE RESULTS!!!
- FACT (ACT) Sheets
a. Newborn screening ACT sheets for providers
b. Provide actions for the professional to follow after receiving a screening report with a possible presence of a condition
