Supplemental Newborn Screen, Blood Spot

Reporting Name

Supplemental Newborn Screen, BS

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Useful For

Presymptomatic identification of disorders to allow for early initiation of treatment and consequent improvement in the long-term prognosis of affected patients

The conditions identifiable by amino acid and acylcarnitine analysis are detected by supplemental newborn screening using tandem mass spectrometry (MS/MS) as described here.

Analyte (assay platform)	ACMG recommended conditions		Additional conditions/treatment detectable by MS/MS
Analyte (assay platform)	Core condition	Secondary targets	Additional conditions/treatment detectable by MS/MS
Amino acids (MS/MS)
Phe	PKU	BS HPA REG	TPN
Leu/Ile, Val	MSUD		TPN
Met	HCY	Met	TPN, nonspecific liver disease
Cit, Arg, ASA	ASA CIT	ARG CIT-II
Tyr	TYR-I	TYR-II TYR-III	Nonspecific liver disease
GUAC	GAMT
Acylcarnitines (MS/MS)
C0	CUD		Maternal CUD, maternal GA-I, maternal MCAD
C3	CblA, Cbl B MUT PA	Cbl C, Cbl D
C4		IBDH SCAD	FIGLU
C5	IVA	SBCAD	Antibiotics containing pivalic acid
C5-OH	BKT HMG MCC MCD	MGA-I MHBD	Maternal MCC, biotinidase deficiency
C8	MCAD	GA-II MCKAT M/SCHAD
C3-DC		MAL
C10:2		DR
C5-DC	GA-I
C14:1, C16, C18:1	VLCAD	CACT CPT-I CPT-II
C16-OH	LCHAD TFP
m/z 225<399<473			Dextrose infusion
m/z 342 (C8:1)			Artifact often observed in premature neonates
m/z 470 (C16:1OH)			Cefotaxime metabolite
Succinylacetone	TYR-I

This test is not appropriate for metabolic screening of symptomatic patients.

Method Name

Flow Injection Analysis Tandem Mass Spectrometry (FIA-MS/MS)

Additional Testing Requirements

A repeat specimen is required within 1 week of birth for infants tested before they are 12 hours old.

Specimen Required

Patient must be older than 12 hours and less than 1 week of age.

Supplies: Card-Blood Spot Collection Filter Paper (T493)

Preferred: Blood Spot Collection Card

Acceptable: Whatman Protein Saver 903 Paper, Munktell, PerkinElmer 226 filter paper, or local newborn screening card

Specimen Volume: 3 Blood spots

Collection Instructions:

1. Do not use device or capillary tube containing EDTA to collect specimen.

2. Completely fill at least 3 circles on the filter paper card (approximately 100 microliters blood per circle).

3. Let blood dry on the Blood Spot Collection Card at ambient temperature in a horizontal position for 3 hours.

4. Do not expose specimen to heat or direct sunlight.

5. Do not stack wet specimens.

6. Keep specimen dry.

Additional Information:

1. For collection instructions, see Blood Spot Collection Instructions.

2. For collection instructions in Spanish, see Blood Spot Collection Card-Spanish Instructions (T777).

3. For collection instructions in Chinese, see Blood Spot Collection Card-Chinese Instructions (T800).

Specimen Type

Whole blood

Specimen Minimum Volume

1 Blood spot

Specimen Stability Information

Specimen Type	Temperature	Special Container
Whole blood	Ambient (preferred)	FILTER PAPER
	Frozen	FILTER PAPER
	Refrigerated	FILTER PAPER

Reject Due To

Blood spot specimen that shows serum rings or has multiple layers	Reject
Insufficient specimen	Reject
Unapproved filter papers	Reject

Reference Values

An interpretive report will be provided.

Interpretation

The quantitative measurements of the various amino acids, acylcarnitines, and succinylacetone support the interpretation of the complete profile but, for the most part, are not diagnostic by themselves. The interpretation is by pattern recognition. Abnormal results are not sufficient to conclusively establish a diagnosis of a particular disease. To verify a preliminary diagnosis, independent biochemical (ie, in vitro enzyme assay) or molecular genetic analyses are required, many of which are offered by Mayo Clinic Laboratories.

The reports are in text form only; values for the more than 60 analytes and analyte ratios are not provided. A report for a normal screening result is reported as: "In this blood spot sample, the amino acid and acylcarnitine profiles by tandem mass spectrometry showed no biochemical evidence indicative of an underlying metabolic disorder."

A report for an abnormal screening result includes a quantitative result of the abnormal metabolites, a detailed interpretation of the results, including an overview of the results significance, possible differential diagnoses, recommendations for additional biochemical testing and confirmatory studies (enzyme assay, molecular analysis), and a phone number for a contact at Mayo Clinic if the referring physician has additional questions.

Day(s) Performed

Monday through Saturday

Report Available

2 to 3 days

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.