Master's in Genetic Counseling (MGC)

Phenylketonuria Screening in New Jersey

Screening for PKU in the state of New Jersey is performed by a fluorescent ninhydrin method (Wallac). Normal results are those <2.1 mg/dl. Results of 2.1-2.9 are considered equivocal, while those 3.0-3.9 mg/dl are borderline, and results of 4.0-5.9 mg/dl are middle abnormal. Results that are >6 mg/dl are presumptive positive for PKU. A repeat filter paper specimen is required for confirmatory testing.

The follow-up recommendations for PKU screens in the state of New Jersey are as follows:

Newborn Screening Result	Interpretation	Follow-Up Action Recommended
<2.1 mg/dl	within acceptable limits	none
2.1-2.9 mg/dl	equivocal results	A repeat filter paper specimen is requested within 2 days.
3.0-3.9 mg/dl	borderline abnormal	A repeat filter paper specimen is requested within 2 days. If the repeat is abnormal, referral to a metabolic/genetic consultant is available upon MD request.
4.0-5.9 mg/dl	middle abnormal	A repeat filter paper specimen is requested within 2 days. If the repeat is abnormal, referral to a metabolic/genetic consultant is available upon MD request.
4.0-5.9 mg/dl with <24 hours of protein feeding	middle abnormal	A filter paper specimen for confirmatory testing, along with a referral to a metabolic/genetic consultant, is recommended within 2 days.
6 mg/dl or greater	presumptive positive	It is recommended that the infant be examined and a filter paper specimen for confirmatory testing be obtained within 2 days. Referral to a metabolic/genetic consultant is also recommended.

 

Note:

It is strongly recommended that the regional consultants be contacted for infants with presumptive positive results or with second borderline abnormal results. Physicians who wish to secure the serum specimens themselves may proceed as follows:

• Collect 2 ml. of venous blood in a red-top vacutainer or a microtainer to yield 1 ml. of serum required for test (Alternatively, 3 ml. of venous blood may be drawn in a heparinized tube. Spin blood and send serum or plasma only).

• Mail serum specimens for PKU testing FIRST CLASS (Preferred over Federal Express or Overnight Delivery) to:

  New Jersey State Department of Health and Senior Services
  Inborn Errors of Metabolism Laboratory
  PO BOX 371
  Trenton, New Jersey 08625-0371
  (609) 292-3090

• For hand delivery or express mail:

  New Jersey State Department of Health and Senior Services
  Inborn Errors of Metabolism Laboratory
  John Fitch Plaza
  Market & Warren Streets
  Health & Agriculture/Laboratory Building
  3rd floor, L-320
  Trenton, New Jersey 08625-0371

• Please include the patient's name, sex, and date of birth, along with the name, address, and phone number of the physician receiving the test results.

• If additional information is needed, please call the State Newborn Biochemical Screening Program at (609) 292-1582 or the Inborn Errors of Metabolism Laboratory at (609) 292-3090.

 

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