Spinal Muscular Atrophy (Blood)

Testing Laboratory

Department

Diagnostic Genetics

Delphic Registration Code (Alpha Code)

DNAT

Test Code (Numeric Code)

7933

Laboratory Handling

Sample Stability

Transport all bloods between 8 degrees to 24 degrees Celsius to the laboratory within 24-48 hours. If necessary specimens can be refrigerated overnight for transport at the temperatures stated above the following day.

Associated Tests

• Spinal Muscular Atrophy (Guthrie Card)

Synonyms

Familial Motor Neurone Disease,
Motor Neurone Disease,
Kugelberg-Welander,
Werdnig-Hoffman

Turnaround Time

6 weeks

Urgent TAT for neonatal analysis: 5 working days.

Specimen Type

• Whole Blood

Specimen Requirements

Tube/Container Type:

Preferred

• EDTA (Lavender Cap)

Preferred Sample Volume (ml)

4

Paediatric Specimen Requirements

Tube/Container Type:

Preferred

• EDTA (Lavender Cap)

Preferred Sample Volume (ml)

4

Minimum Sample Volume (ml)

0.5

Additional Specimen Information

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.

Test Method

The Multiplex Ligation-dependent Probe Amplification (MLPA) kit P021-B1 SMA from MRC-Holland is used to detect copy number of exons 7 and 8 of SMN1 and SMN2, at region 5q13.2. Testing was performed alongside negative and positive controls. Analysis was performed using Coffalyser.Net. Reference sequence used: SMN1 - NM_000344.4, NP_000335.1 and SMN2 - NM_017411.4, NP_059107.1.

Limitations / Interference

The assay cannot detect point mutations nor can it discriminate between 2 copies of SMN1 on the same chromosome versus 2 copies on separate chromosomes.

Contact Information