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Genetic mutation screening for *Glycogen Storage Disease Type I (von Gierke disease) – Glucose-6-Phosphatase Deficiency* (G6PD)

Published: August 9, 2026Updated: August 16, 2026

This test checks for genetic changes linked to a rare metabolic disorder called Glycogen Storage Disease Type I (GSD I), also known as von Gierke disease. These changes affect how your body processes glucose, a key energy source.

Quick summary

["Helps identify if you carry mutations that may cause GSD I, a condition affecting glucose metabolism."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
48977-3
Short code
SGCG gene Mut Anl Bld/T
Synonyms
SGCG gene Mut Anl Bld/T
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
molgen
Specimen volume
3 mL
Stability
Room temperature: 4h, Refrigerated: 24h
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why This Test Might Be Ordered

Your healthcare provider may recommend this test if you have symptoms like frequent hypoglycemia (low blood sugar), enlarged liver or spleen, or a family history of GSD I. It’s also sometimes done as part of prenatal testing if there’s a known risk in your family.

How the Test Works

Blood is drawn to collect a sample for genetic analysis. Specialized lab techniques identify any mutations in the *G6PD* gene, which can cause GSD I.

What to Expect Before the Test

No special preparation is needed, but avoid strenuous activity the day of your test. Fasted blood samples are sometimes used for metabolic-related tests, but this one focuses on genetics.

What to Expect During the Test

A healthcare provider will insert a needle into your arm to draw blood. You may feel a slight pinch, but it’s usually over quickly. The process takes about 5 minutes.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Positive results indicate a genetic risk for GSD I, which can cause severe health issues if untreated. Early diagnosis allows for management strategies, such as dietary adjustments or enzyme replacement therapy. This test is primarily for screening and confirmation of inherited conditions, not diagnostic of acute symptoms.

Short name

G6PD Mutation Screening

Frequently asked questions

What Does This Test Measure?
This test detects specific mutations in the *G6PD* gene that are associated with Glycogen Storage Disease Type I. It does not measure enzyme activity or glucose levels directly.
Will This Test Show If I Have GSD I?
No. This test only identifies genetic mutations linked to GSD I. A diagnosis of the condition requires clinical evaluation, including symptoms, family history, and sometimes additional tests like enzyme assays.
How Often Should I Get This Test?
Only if recommended by your healthcare provider—typically as part of genetic counseling, prenatal screening, or if you have symptoms or a family history of GSD I.
  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 16, 2026. · Read our editorial policy