Fragile X Syndrome (Blood)

Testing Laboratory

Department

Diagnostic Genetics

Delphic Registration Code (Alpha Code)

DNAT

Test Code (Numeric Code)

7933

Laboratory Handling

Transport

Transport all bloods at room temperature within 24-48 hours. If necessary, specimens can be refrigerated overnight for transport at room temperature the following day.

Registration

Please store specimens at 4 degrees C until processed.

Sample Stability

24 to 48 hours at room temperature.

Associated Tests

• DNA Extraction and Storage (Blood)

Synonyms

FMR1 gene testing

Turnaround Time

6 weeks

Urgent TAT for prenatal 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

Additional Specimen Information

Transport all bloods at room temperature within 24-48 hours. If necessary specimens can be refrigerated overnight for transport at room temperature the following day.

For testing of other sample types please contact the laboratory prior to sending.

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

REFERRAL REQUIREMENTS:

Diagnostic referral 15yrs requires referral through Neurology, Psychiatry or Genetic Services.

All predictive/carrier only through Genetic Services.

Premature ovarian failure referrals can be accepted through Obstetrics.

LabPlus does NOT perform Fragile X analysis for preconception carrier testing unless there is a proven family history or the patient has clinical features consistent with a diagnosis of Fragile X syndrome.

IMPORTANT NOTES: Clinical details must be provided. Failure to provide the relevant details may delay testing.

Test Method

The Asuragen AmplidexTM FMR1 PCR kit and fluorescence-based capillary electrophoresis are used to detect CGG repeat expansions within the FMR1 gene - NM_002024.6, NP_002015.1. Due to the nature of the assay, we estimate that the CGG repeat allele sizing is correct to +/-1 repeat for alleles within the normal to intermediate range, and +/-2 repeats for alleles within the premutation range.

Limitations / Interference

This test cannot exclude the possibility of mosaicism; it cannot exclude the possibility of a null allele due to the inability of the primers to bind (as a consequence of variant genomic sequences); it cannot detect a deletion or point mutation within the FMR1 gene.

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.

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

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

Contact Information