Specimen:

Whole Blood

Collection Medium:

Minimum:

Adults - 3 mL whole blood in lavender top tube (EDTA)
Children - 2 mL whole blood in lavender top tube (EDTA)
Testing on smaller volumes than those requested will be attempted.  
However, in some cases, small blood volumes may compromise the ability 
to perform testing.
Testing requires a dedicated collection tube.

Testing
Schedule:

Weekly

Analytic Time:

21 days

Reference Range:

Normal: <35 CTG repeats
Indeterminate: 35-49 CTG repeats
Carrier: 50-99 CTG repeats
Full mutation (affected): >99 CTG repeats

Methodology:

Polymerase Chain Reaction (PCR) and Southern Blot

Sample
Processing:

Do Not Centrifuge.
Label transport tube with two patient identifiers, date and time of 
collection.
Patient's age and sex is required on requisition for processing.
Relevant clinical information must be submitted with specimen in order 
to provide correct interpretation of test results.
Submit whole blood in original container.

Sample
Storage:

Room temperature for up to 24 hours, then refrigerate the whole blood 
if it is necessary to be held overnight, or weekends, or holidays.

Transport
Instructions:

Recommend express mail or equivalent if not on courier service.
Place requisition into outside pocket of bag.
Ship at ambient temperature.

CPT Code:

83890, 83892(x3), 83894, 83896, 83897, 83898, 83912

See Additional Information:
Myotonic Dystrophy DNA Information