Order or find a test

The National Genomic Test Directories specify which genomic tests are commissioned by the NHS in England, to be delivered by Genomic Laboratory Hubs.

Clinical Indication ID & Name

R410

Myotonic dystrophy type 2 (DM2)

Test Group

Neurology

Specialties

Clinical Genetics Neurology

Test code

R410.1

Test name

N/A

Target genes

CNBP (ZNF9) STR

Test scope

n/a

Test method/ technology

STR testing

Optimal Family Structure

n/a

Eligibility Criteria

1. Adult with muscle weakness, usually proximal, and one of the following:
a. Clinical Myotonia: of grip or on percussion
b. EMG evidence of myotonic discharges
c. Cataracts (fine dust like opacities on the outer layers of the lens that are highly coloured and iridescent, producing a “Christmas Tree” appearance)
d. Three or more supportive features (from list below)
e. Family History suggestive of autosomal dominant inheritance
2. AND DM1 excluded first if the clinical presentation/Family history could easily fit DM1
3. OR Family history of mutation positive DM2
Additional supportive features:
• Elevated serum CK
• Insulin-insensitive type 2 diabetes
• Testicular failure
• Cardiac conduction defects
• Low serum IgG or IgM
• Muscle biopsy showing atrophic fibres and proliferation of fibres with central nuclei
• Excessive daytime sleepiness
• Mildly elevated liver function tests (LFT)
• Muscle pain

Commissioning group

Specialised

Overlapping idications

• R72 Myotonic dystrophy type 1 should be used prior to this indication unless there is clinical suspicion of myotonic dystrophy type 2 • R381 Other rare neuromuscular disorders should be used where clinical features are atypical and a broader range of genes are potentially causative

Address for samples/request forms

Genetics Laboratory
5th Floor Tower Wing
Guy’s Hospital
London
SE1 9RT

Contact with queries

gst-tr.southeastglh@nhs.net

Supporting documents

n/a

Education resources

n/a

Turn around times

All our turnaround times are listed on our specific turn around page https://southeastgenomics.nhs.uk/professionals/service-turn-around-times/

Request form download

Rare Disease Order Form Record of Discussion Form

Consent record

See consent guidance in test request form

Sample requirements

Samples may be rejected for the following reasons: 1.Samples and request form do not show at least three identical patient identifiers 2.The sample is in the incorrect collection media 3.The request form is not sufficiently completed 4.The sample is not of sufficient volume 5.The sample is too old