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Alpha-N-acetylgalactosaminidase, Dried Blood Spot — Catalytic Concentration

Published: August 9, 2026Updated: August 17, 2026

Measures the activity of the alpha-N-acetylgalactosaminidase enzyme in a dried blood spot to help evaluate certain rare inherited metabolic disorders.

Quick summary

["Low enzyme activity may indicate an inherited deficiency, but screening results usually require confirmatory testing."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
79455-2
Short code
A-NAGA DBS-cCnc
Synonyms
A-NAGA DBS-cCnc
Category
liver
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
0
Ref high
2
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
86038
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What is this test?

This test measures the activity of alpha-N-acetylgalactosaminidase, an enzyme involved in breaking down complex sugars. A small blood sample is placed on a filter card and dried before being analyzed.

Why might I need this test?

This test is most often used in newborn screening or when a clinician suspects a lysosomal storage disorder. Reduced enzyme activity can occur with inherited conditions affecting how the body processes certain carbohydrates.

How is the test performed?

A blood sample is collected from a finger prick or heel stick and placed on a special filter card. The card is dried and sent to a laboratory, where the enzyme activity is measured.

How do I prepare for the test?

No fasting is usually required for a dried blood spot test. Follow the instructions provided by the screening program or clinic, and tell the clinician if the person has recently received a blood transfusion.

Reference range

NCBI: SCC <2.0 ng/mLN/A

Specimen: serum

No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Alpha-N-acetylgalactosaminidase (DBS)

Frequently asked questions

Does this test diagnose a specific disorder?
Not by itself. It screens for reduced enzyme activity, and abnormal results usually need confirmatory testing before a disorder is diagnosed.
Is fasting required for this test?
Fasting is generally not required for a dried blood spot test. Follow any specific instructions from the clinic or newborn screening program.
What if the result is abnormal?
The healthcare provider may order repeat or confirmatory testing using another specimen, along with genetic or clinical evaluation. Results should be interpreted by a clinician familiar with newborn screening or inherited metabolic disorders.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 17, 2026. · Read our editorial policy