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R454  Mavacamten for treating symptomatic obstructive hypertrophic cardiomyopathy (CYP2C19 genotyping to guide mavacamten dosing)

Step by step instructions

Eligibility

Testing is available to patients with:
1.    Symptomatic obstructive hypertrophic cardiomyopathy who have a New York Heart Association class of 2 to 3 AND
2.    are eligible for treatment with mavacamten in line with NICE TA 913 (where mavacamten is an add on to individually optimised standard care that includes beta blockers, non-dihydropyridine calcium-channel blockers or disopyramide, unless these are contraindicated).

NICE guidance https://www.nice.org.uk/guidance/ta913

 

Eligibility criteria for genomic tests can be found in the National Genomic Test Directory.

This lists the clinical specialties that would be expected to request for a given clinical indication and sets out which patients should be considered for testing.

Test order form

The GMS test order form is available below:

This should be completed in full & include the test indication ‘R454 – Mavacamten for treating symptomatic obstructive hypertrophic cardiomyopathy (CYP2C19 genotyping)’.

Alternatively, local test request forms with the equivalent information are acceptable.

Samples and transport

•    Please ensure that the patient identity has been verified before taking the sample.
•    The sample should be labelled with at least 3 patient identifiers including the patient’s name & date of birth.
•    Please send the completed referral form and the labelled patient sample (2-4ml of EDTA blood) to the designated Genomics Laboratory Hub:

South West Genomics Laboratory Hub
Bristol Genetics Laboratory
Southmead Hospital
Westbury-on-Trym
Bristol
BS10 5NB

 

  • Samples should be sent at room temperature. If there is a delay in sending the sample can be refrigerated at +4 degree Celsius for a few days without affecting quality.
  • The sample container should be leak-proof and must be placed in a transparent sample bag with the paperwork attached but not in the same compartment as the container. The outer sample packaging must comply with PI 650 for category B substances. The package should be clearly labelled ‘diagnostic specimen UN3373’.
  • Samples should be sent first class via the Royal Mail postal services.

Before sending samples for genomic testing, please ensure you follow the correct preparation and transport guidelines. This includes information on sample types, volumes, handling, labelling, and packaging standards.

For a full list of sample requirements and transport guidance, please visit the samples and transport page of the website. 

Test methodology

  • LAMP coupled melt-curve analysis is used to genotype 3 clinically relevant variants in the CYP2C19 gene: c.681G>A (CYP2C19*2), c.636G>A (CYP2C19*3) and c.-806C>T (CYP2C19*17)

Results and turnaround times

•    Reports will be returned by email within 5 days as a pdf-document.
•    Report recipient details (name, job title and email address) should be specified on the referral form.
•    Alternatively, the GLH will manage a list of recipients for your region; contact kenneth.smith@nbt.nhs.uk at the SWGLH to discuss what information is required to set this up.