Mito - Cascade and family testing
Overview
Relatives of a patient previously diagnosed with a specific mutation may be tested for the same mutation.
Testing depends upon the mutation type identified in the relative:
Nuclear DNA: cascade testing is via Sanger sequencing on an EDTA blood sample
mtDNA: cascade testing is via NGS panel for the specific mutation- blood, liver, muscle or urine samples are suitable depending upon the condition.
Category
Cost
Nuclear DNA:
$340 (per variant)
$440 (per externally identified variant)
mtDNA:
$700 (per variant)
$800 (per externally identified variant)
Reporting time
6-8 weeks
Contacts
P: 1300 11 8247
E: [email protected]
Specimen Requirements
Nuclear DNA:
| Sample Type | Sample Volume |
|---|---|
| EDTA blood | Adult: 4ml; Child: 2ml |
| Saliva |
ORACollect kit |
mtDNA:
| Sample Type | Sample Volume |
|---|---|
| EDTA blood | Adult: 4ml; Child: 2ml |
| Saliva | ORACollect kit |
| Liver/Muscle | 1-5mg |
| Urine# (for Adults >30 years) |
10-20ml (early morning) |
#Urine is recommended in adults >30 years old as the mutation can disappear from blood with age, in particular individuals suspected of MELAS for the m.3243A>G mutation. Please note critical collection, storage and transport requirements for urine - detailed below.
Important notes for specimen storage and handing:
- EDTA blood: Store at 4°C or room temperature. Do NOT freeze.
- Urine: Early morning collection, frozen fresh (store at -20°C/freezer if patient collected at home/clinic), transport to lab on dry ice. To be stored at -70°C if not extracted immediately.
- Tissue biopsy/autopsy samples: Must be stored at -70°C (-20°C is inadequate) until transport on dry ice. Once frozen, they must not be allowed to thaw.
- Postmortem Samples: COLLECT AS SOON AFTER DEATH AS POSSIBLE, preferably within 2 hours. Note the time between death and freezing of samples.
- Liver and muscle tissue samples should be no larger than 1.0 cm cubes; heart, kidney & brain samples may also be collected.
- Enzymes can be assayed in postmortem heart but endomyocardial microbiopsies are too small.
Notes
Please provide the following clinical details (if available) to enable optimal interpretation:
- Patient name, medical record no., date of birth, date of sample, delay between death and freezing if relevant.
- Full clinical summary and family history with pedigree.
- Include copies of relevant investigations
- urine organic & amino acids
- tissue histology (including electron microscopy & enzyme histochemistry)
- summary of CT, MRI or MRS studies of brain.
- Paired plasma lactate & pyruvate levels; multiple estimations preferred.
- Paired CSF lactate & pyruvate levels, preferably with blood levels obtained at about the same time.