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Test Code MULT Zygosity Testing (Multiple Births), Varies

Genetics Test Information

DNA from twins and their parents is used to determine if the twins are identical (monozygotic) or fraternal (dizygotic).

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
CULFB Fibroblast Culture for Genetic Test Yes No
CULAF Amniotic Fluid Culture/Genetic Test Yes No
_STR1 Comp Analysis using STR (Bill only) No No
_STR2 Add'l comp analysis w/STR (Bill Only) No No

Specimen Type

Varies


Shipping Instructions


Specimen preferred to arrive within 96 hours of collection.



Necessary Information


A blood specimen from both parents, in addition to a specimen from each multiple, is required.



Specimen Required


Patient Preparation: A previous bone marrow transplant from an allogenic donor will interfere with testing. For instructions for testing patients who have received a bone marrow transplant, call 800-533-1710.

 

Submit only 1 of the following specimens:

 

Specimen Type: Whole blood

Container/Tube: Lavender top (EDTA) or yellow top (ACD)

Specimen Volume: 3 mL

Collection Instructions:

1. Invert several times to mix blood.

2. Send specimen in original tube. Do not aliquot.

Specimen Stability Information: Ambient (preferred)/Refrigerated

 

Prenatal Specimens

Due to its complexity, consultation with the laboratory is required for all prenatal testing; call 800-533-1710 to speak to a genetic counselor. 

 

Specimen Type: Amniotic fluid 

Container/Tube: Amniotic fluid container 

Specimen Volume: 20 mL 

Specimen Stability Information: Refrigerated (preferred)/Ambient 

Additional information:  

1. A separate culture charge will be assessed under CULAF / Culture for Genetic Testing, Amniotic Fluid. An additional 2 to 3 weeks is required to culture amniotic fluid before genetic testing can occur. 

2. All prenatal specimens must be accompanied by a maternal blood specimen; order MATCC / Maternal Cell Contamination, Molecular Analysis, Varies on the maternal specimen. 

Specimen Type: Chorionic villi 

Container/Tube: 15-mL tube containing 15 mL of transport media 

Specimen Volume: 20 mg 

Specimen Stability Information: Refrigerated 

Additional Information:  

1. A separate culture charge will be assessed under CULFB / Fibroblast Culture for Biochemical or Molecular Testing. An additional 3 to 4 weeks is required to culture fibroblasts before genetic testing can occur. 

2. All prenatal specimens must be accompanied by a maternal blood specimen; order MATCC / Maternal Cell Contamination, Molecular Analysis, Varies on the maternal specimen. 

 

Acceptable: 

Specimen Type: Confluent cultured amniocytes 

Container/Tube: T-25 flask 

Specimen Volume: 2 Flasks 

Collection Instructions: Submit confluent cultured amniocytes from another laboratory. 

Specimen Stability Information: Ambient (preferred)/Refrigerated 

Additional Information: All prenatal specimens must be accompanied by a maternal blood specimen; order MATCC / Maternal Cell Contamination, Molecular Analysis, Varies on the maternal specimen. 

 


Specimen Minimum Volume

Blood: 0.5 mL
Amniotic Fluid: 10 mL
Chorionic Villi: 5 mg

Specimen Stability Information

Specimen Type Temperature Time Special Container
Varies Varies

Reject Due To

All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Reference Values

An interpretive report will be provided.

Day(s) Performed

Monday

Report Available

5 to 12 days

Specimen Retention Time

Whole Blood: 2 weeks (if available) Extracted DNA: 3 months

Performing Laboratory

Mayo Clinic Laboratories in Rochester

CPT Code Information

81265-Comparative analysis using Short Tandem Repeat (STR) markers; patient and comparative specimen (eg, pre-transplant recipient and donor germline testing, post-transplant non-hematopoietic recipient germline [eg, buccal swab or other germline tissue sample] and donor testing, twin zygosity testing or maternal cell contamination of fetal cells

 

88233-Tissue culture, skin or solid tissue biopsy (if appropriate)

88235-Tissue culture for amniotic fluid (if appropriate)

88240-Cryopreservation (if appropriate)

81266-Each additional specimen (eg additional cord blood donor, additional fetal samples from different cultures, or additional zygosity in multiple birth pregnancies) (as needed)