Sign in →

Test Code LAB1905 Molecular Genetics Lab Hold

Important Note

Molecular Genetics Lab Hold requests are restricted to clinical lab testing ordered by Seattle Children's Hospital providers only. 

This request may only be used for tests for which EXTRACTED DNA is an acceptable sample type.  This request CANNOT be used for karyotype or FISH (Fluorescent in-situ hybridization) requests.

BEFORE ordering MGL hold  for collection we strongly suggest that each case is discussed with a  Lab Genetic Counselor. It may not be necessary to draw blood if previous genetic testing has been performed by SCH Genetics Lab. 

MGL hold requests are limited to the following circumstances:

  • One specific clinical molecular test is planned, AND
  • An alternative specimen collection (e.g. saliva, buccal) is not an option; AND
  • There is a significant hardship to deferral of sample collection until after genetic test preauthorization is obtained; AND
  • Criteria for use of long-term DNA storage service (DNA Bank) are not met.

After sample collection, all requests will be reviewed for approval by the Lab Genetic Counselor team, 206-987-5400 or LabGC@seattlechildrens.org.  Genetic testing must be approved by the Lab Test Stewardship Team. Some samples may be discarded if specified criteria are not met.

Clinical System Name

Molecular Genetics Lab Hold

Description

To minimize the risk of excessive financial liability for patient family and the organization, an insurance pre-authorization outcome must be obtained prior to ordering genetic testing (Policy & Procedures: Insurance Pre-Authorization for Genetic Testing).  

 

Best practice is deferral of sample collection until the insurance pre-authorization outcome is determined. Short-term DNA storage (maximum 1 year) at SCH Laboratory is available for the rare instances when a sample collection cannot be deferred during the pre-authorization process. This service, MGL Hold,  should be used only when an alternative sample collection (saliva, buccal) cannot be utilized for the requested test and it is a signficant hardship for a family to return to a SCH laboratory for sample.  

 

Upon receipt of approved add-on test requests, the entire amount of stored DNA will be sent to specified lab for testing.  Samples will not be aliquoted or split to enable testing plus continued storage. DNA not utilized for testing within one year of the date of collection will be discarded.  MGL hold samples are restricted to clinical use only.   

Sample Requirements

Specimen: Whole blood

Container(s): Lavender/EDTA

Preferred Vol: 3 mL

Minimum Vol: 1 mL

Note: Smaller whole blood volumes may yield suboptimal amounts of DNA.  If the minimum amount of blood cannot be obtained, consider deferring collection.

 

Specimen: Skin punch biopsy

Container: Sterile cup or tube

Preferred Vol:  3-4mm

Minimum Vol: 2mm

Also acceptable: Punch biopsy may be frozen in sterile tube with no media or refrigerated with 1-3 mL of tissue transport medium. DO NOT use formaldehyde, formalin, alcohol, or 5% dextrose.

  

Specimen: Cultured fibroblasts from SCH Cytogenetics Lab*

Container(s): T-25 flasks

Preferred Vol: 2 flasks

*Link to Cytogenetic tissue culture and storage - specimen requirements, instructions and CPT codes

Processing Instructions

Reject due to: Heparin

Spin: No

Aliquot: No

 

Specimen Type Description Temperature Storage instructions
Whole blood EDTA tube Refrigerate Molecular Genetics box in CPA refrigerator #2
Skin biopsy Sterile container Frozen Molecular Genetics box in CPA -70 freezer
In medium Refrigerate Molecular Genetics box in CPA refrigerator #2
Body fluid or blood Cell-free DNA tube Room Temp Molecular Genetics Room Temp box in CPA

Off-site SCH clinic collection: Refrigerate blood samples for storage and shipping.

Stability

Specimen Type Temperature Time
Whole blood Refrigerated 5 days
Tissue - Fresh Frozen -70 C years
Tissue in medium Refrigerated 2 days

Availability

Performed
Monday - Friday

 

Performing Laboratory

Seattle Children's Laboratory

Department

Department:  Molecular Genetics Laboratory, labdnabank@seattlechildrens.org

Phone: 206-987-3872

 

Lab Client Services: 206-987-2617, labclientservices@seattlechildrens.org

 

Lab Genetic Counselor: LabGC@seattlechildrens.org

Reference Range

A result documenting a sample is being held and the discard date will post to chart.

Clinical Utility

The use of MGL hold should be discussed with a genetic counselor or geneticist or other provider.
 

Limitations of service: 

  1. Not all reference labs accept extracted DNA for testing.  Verify specimen requirements for required testing before ordering MGL hold.
  2. Occasionally, suboptimal extracted DNA performance has been reported by reference labs during testing.  In these cases, specimen recollection is required.