MLH1 Gene Methylation Status in Blood (24-Hour Collection)
This test checks how DNA in your blood cells is chemically modified (methylated) at the MLH1 gene, which plays a key role in preventing certain genetic errors that can lead to cancer.
["This test helps assess your risk for hereditary cancer syndromes linked to DNA repair defects."]
Key facts at a glance
- LOINC
- 58416-9
- Short code
- MLH1 gene methylation Bld/T Ql
- Synonyms
- MLH1 gene methylation Bld/T Ql
- Category
- chemistry
- Sample
- whole-blood
- Container
- Lavender-top (EDTA)
- Units
- N/A
- Ref low
- 1.5
- Ref high
- 9
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- molgen
- CPT
- 83002
- 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 a family history of certain cancers (such as colorectal, stomach, or ovarian cancer) or if you’ve been diagnosed with one of these cancers at a younger age than expected. It could also be part of a broader genetic evaluation for conditions like Lynch syndrome.
What to Expect Before the Test
You’ll need to provide a blood sample, typically drawn from a vein in your arm. No special preparation is usually required, but your provider may ask you to avoid certain medications or supplements for a short time before testing.
What the Test Measures
The test looks at the methylation (chemical tagging) of the MLH1 gene in your white blood cells. Methylation can silence genes, and abnormal patterns may indicate a higher risk for inherited cancer syndromes.
What the Results Might Mean
Results are qualitative (yes/no) and describe whether the MLH1 gene shows normal or abnormal methylation. Abnormal methylation could suggest a genetic predisposition to Lynch syndrome or other hereditary conditions, but it doesn’t confirm cancer risk alone—further genetic testing may be needed.
Reference range
Follicular: 1.5-9.0 mIU/mLN/A
For females: inform if menstrual cycle status. For certain tests, timing within menstrual cycle may matter.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
MLH1 methylation is associated with Lynch syndrome, an inherited condition that increases the risk of multiple cancers, including colorectal, endometrial, and ovarian cancers. Detecting abnormal methylation can help guide preventive strategies, such as closer monitoring, risk-reducing surgeries, or chemoprevention.
Short name
MLH1 Methylation Test
Frequently asked questions
What does a positive or abnormal result mean?
Will this test show if I already have cancer?
How often should I get this test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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