Malignant Hyperthermia - 9
Molecular Genetic Diagnostic Testing
- Not a screening test. Among patients with postive CHCT, genetic test sensitivity is 30-40%.
- Absence of mutation does not rule out MH
- Referral for testing should be made only by physician or genetic counselor
- Blood sample is all that is needed for testing
- Does not replace the CHCT. Those without a mutation on genetic test should be referred for CHCT to determine MH susceptibility.
- If a known MH mutation is found, other family members with that mutation are MH-susceptible for certain and may bypass the CHCT
- Will presently detect only about 30% of those at risk. However, the genetic test is very specific -- that is, those with a positive test are virtually assured of being at risk for MH.
In order to increase the sensitivity of the test, MHAUS advises that only the following individuals be considered for the test:
a. Those who have been tested positive by the contracture test.
b. Relatives of those who have been tested positive by the contracture test.
c. Those who have been found to have a mutation causative for MH under a
d. Relatives of those with a known mutation for MH.
e. Those with a very high likelihood of having experienced an MH episode.
- Cost to assess DNA for presence known mutations is about $800 (partial test) to $4,000 (full gene sequencing). Cost to assess a family member for one specific mutation is about $200.
- Testing centers
- See MHAUS for more details