MH Malignant hyperthermia

DNA test DNA test for the Malignant hyperthermia (MH). This test verifies the presence of the dominant MH gene and presents...

€43.05

Sample Requirements

30 to 40 - hair roots - envelope or 5 mL - blood - K3 EDTA tube

Send your sample by regular mail or express delivery to:

Equigerminal Lab HIESE
Rua da Quinta do Sobreiro Nº25
3230-343 Penela, Portugal

Turnaround Time

2 to 5 working days

About the test

This DNA test detects the Malignant Hyperthermia (MH) mutation, an inherited genetic disorder affecting skeletal muscle function in Quarter Horses and related breeds.

The test identifies whether a horse is clear or affected by the dominant MH mutation, supporting breeding decisions and clinical management before anaesthesia or intense exercise.

Why test?

This genetic test helps to:

Identify horses carrying the dominant MH mutation.
Support responsible breeding decisions.
Assess the risk of malignant hyperthermia before anaesthesia.
Identify horses at increased risk of exercise- or stress-induced muscle crises.
Detect horses that may also benefit from additional PSSM1 testing.

How it works

🛒 Purchase the Test: Select and buy the test online.

📧 Receive Instructions: After payment confirmation, receive instructions for sample collection.

✨ Sample Collection: Your veterinarian collects hair roots or a blood sample.

📄 Download Submission Form: Download the printable submission form.

📮 Send Samples: Send your samples by regular mail or express delivery to:

Equigerminal Lab HIESE
Rua da Quinta do Sobreiro Nº25
3230-343 Penela, Portugal

📄 Receive Results: Get your result certificate by email.

Results

The DNA test verifies the presence of the dominant MH gene and presents results as one of the following:

N/ - Negative for MH.Absence of the allele responsible for Malignant Hyperthermia (MH).
MH/N - Affected - Positive heterozygous for MH. Presence of one copy of the allele responsible for MH. The horse is affected with the MH disorder and can pass the MH alleleto 50% of their progeny when bred.
MH/ -Affected - Positive homozygous for MH. Presence of two copies of the allele responsible for MH.The horse is affected with the MH disorder and will pass the MH allele to 100% of its offspring.

Additional information

Malignant Hyperthermia (MH) is a genetic muscle disorder inherited as an autosomal dominant trait, meaning that a single copy of the mutation is sufficient to cause the condition.

Affected horses may appear completely healthy until exposed to triggering factors such as general anaesthesia, intense exercise or severe stress. Clinical signs develop rapidly and may include high body temperature, muscle rigidity, excessive sweating, increased heart rate, elevated blood pressure, metabolic acidosis and, in severe cases, sudden death if treatment is not initiated promptly.

The mutation is most commonly found in Quarter Horses and related breeds. Horses carrying both the MH and PSSM1 mutations may experience more severe clinical signs than horses affected by either condition alone. For this reason, simultaneous testing for MH and PSSM1 is recommended in susceptible breeds.

Knowing a horse's MH status allows veterinarians to adapt anaesthetic protocols and implement preventive measures to reduce the risk of life-threatening episodes.

FAQs

Which samples can be submitted?

The test can be performed using 30–40 hair roots or 5 mL of blood collected in a K3 EDTA tube.

Why should I test for Malignant Hyperthermia?

Testing identifies horses carrying the MH mutation, allowing informed breeding decisions and helping veterinarians reduce anaesthetic risks through appropriate management.

Which horses are most commonly affected?

The mutation is primarily found in Quarter Horses and related breeds, although testing may be appropriate whenever there is a relevant pedigree or clinical suspicion.

Should I also test for PSSM1?

Yes. Horses carrying both MH and PSSM1 mutations can develop more severe clinical signs, so testing for both conditions is recommended in susceptible breeds.

How long does it take to receive the results?

Results are available within 2 to 5 working days after sample arrival at the laboratory.