Myotonic Dystrophy (Blood)

Testing Laboratory

Department

Diagnostic Genetics

Delphic Registration Code (Alpha Code)

DNAT

Test Code (Numeric Code)

7933

Laboratory Handling

Transport

Transport all bloods between >8 degrees C to <24 degrees C within 24-48 hours. If necessary specimens can be refrigerated overnight for transport at the temperatures stated above the following day. For testing of other sample types please contact the laboratory prior to sending.

Registration

Please store specimens at 4 degrees Celsius until processed.

Sample Stability

48 hours at ambient temperature (8 degrees C to 24 degrees C).

Associated Tests

• DNA Extraction and Storage (Blood)

Synonyms

Myotonic dystrophy genetic testing
Myotonic Dystrophy Type 1 Testing

Turnaround Time

6 weeks

Urgent TAT for prenatal/neonatal analysis: 2 weeks

Specimen Type

• Whole Blood

Specimen Requirements

Tube/Container Type:

Preferred

• EDTA (Lavender Cap)

Acceptable

• EDTA (Microtainer)

Preferred Sample Volume (ml)

8

Minimum Sample Volume (ml)

4

Paediatric Specimen Requirements

Tube/Container Type:

Preferred

• EDTA (Lavender Cap)

Acceptable

• EDTA (Microtainer)

Preferred Sample Volume (ml)

4

Minimum Sample Volume (ml)

0.5

Aliquot Instructions

Sample Type

• Whole Blood

Minimum Volume (ml)

4

Transport to Lab

Ambient (8 - 24 degrees Celsius)
If overnight - Chilled (2 - 8 degrees Celsius)

Additional Referral/Aliquot Information

Important Notes:

Diagnostic testing requires referral through Neurology, Paediatrics or Genetic Services.

Predictive testing only through Genetic Services.

The clinical presentation should be provided. Failure to provide the clinical detail required may delay testing.

Contacts:

Genetic Health Service NZ can be contacted on 0800 476 123.

Neurology can be contacted on (09) 307 4949 ext. 25662.

General Paediatrics can be contacted on (09) 307 4949 ext. 22559.

Test Method

A standard PCR-based amplification and subsequent fluorescence-based capillary electrophoresis are used to detect CTG repeat expansions within the DMPK gene - NM_004409.5. Forward and reverse Triplet-repeat Primed (TP) PCR amplification and subsequent fluorescence-based capillary electrophoresis are used to detect all sizes of expansion within the DMPK gene. Due to the nature of the assays, we estimate that the number of each CTG repeat is correct to within plus or minus one for alleles within the normal range, and up to plus or minus three for alleles within the affected range up to 150 repeats.

Uncertainty of Measurement

Please contact the Diagnostic Genetics Pathologist at dgen@adhb.govt.nz to discuss sources of test uncertainty, which include, but are not limited to, measurement uncertainty (MU) and biological variation.

Contact Information