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MUTATION STATUS FOR MSH2 AND MLH1 GENES (BLOOD)

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

This test checks for genetic mutations in the MSH2 and MLH1 genes, which are involved in repairing errors in DNA during cell division. These mutations can increase the risk of certain cancers.

Quick summary

["This test helps assess inherited cancer risk by detecting gene changes linked to Lynch syndrome."]

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

Key facts at a glance

LOINC
32630-6
Short code
MSH2+MLH1 gene Mut Anl Bld/T
Synonyms
MSH2+MLH1 gene Mut Anl Bld/T
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

Your doctor may order this genetic test if you have a personal or family history that suggests an inherited condition could be present. The results can help explain a pattern of illness in your family, guide decisions about screening or treatment, and give relatives useful information about their own health risks.

Your healthcare provider may recommend this test if you have a strong family history of certain cancers (like colon, endometrial, 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 genetic screening or counseling process.

Before the test, you will usually meet with a doctor or genetic counselor to review your medical and family history and discuss what the results could mean. You may be asked to sign a consent form, and then a blood or saliva sample will be collected. No fasting or special preparation is typically needed.

You’ll provide a small sample of whole blood, usually drawn from your arm. The process is quick and similar to a regular blood draw. No special preparation is needed, but inform your provider about any medications or health conditions you have.

This test looks at specific genes for inherited changes, called mutations or variants, that can affect your health. By examining the DNA in your sample, the laboratory can identify whether you carry a change that has been linked to a higher risk of certain medical conditions.

The test looks for specific changes (mutations) in the MSH2 and MLH1 genes. These genes help fix mistakes in DNA that can lead to cancer over time. If mutations are found, it may indicate a higher risk for Lynch syndrome-related cancers.

A positive result means a mutation was found and may increase your risk of developing certain health problems. A negative result means no mutation was detected in the genes studied. Some results are uncertain, or inconclusive, and your care team will explain what your specific result means for you.

Results can be one of three main types: *Negative*: No mutations found in these genes. *Positive*: Mutations detected, suggesting a higher risk for Lynch syndrome-related cancers. *Inconclusive*: The test may not have detected mutations, or further testing may be needed.

Reference range

Follicular: 1.5-9.0 mIU/mLN/A

Specimen: whole-blood

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.

Clinical Significance

Short name

MSH2/MLH1 Mutation Blood Test

Frequently asked questions

If mutations are found, your healthcare provider will discuss next steps, which may include closer monitoring for cancer, additional genetic testing, or preventive measures like regular screenings or surgery.
A positive result means the test found a mutation that may raise your chance of developing certain conditions over time. It does not mean you have the disease now or definitely will get it, but it helps your care team plan earlier screening, prevention steps, or treatment tailored to your risk.
A positive result means you may have a higher risk of certain cancers (like colon, stomach, or endometrial cancer) due to Lynch syndrome. Your provider will help you understand your risks and recommend personalized follow-up plans.
If a mutation is found, your doctor will usually recommend a personalized follow-up schedule, which may include exams, imaging, or blood tests every few months or once a year. The exact plan depends on the specific mutation and your overall health, so ask your care team what timing is right for you.
Follow-up frequency depends on your specific mutation and family history. Your provider will tailor recommendations, which may include regular cancer screenings (like colonoscopies) or other monitoring strategies.
Yes, while mutations in these genes increase cancer risk, they’re not the only factor. Many people with normal test results still develop cancer. Regular screenings and a healthy lifestyle can help manage risk.
  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