BCH Order Code UNIPD Uniparental Disomy, Varies
Useful For
Evaluation of patients presenting with mosaicism, confined placental mosaicism, or Robertsonian translocations
Evaluation of patients presenting with features of disorders known to be associated with uniparental disomy (eg, Russell-Silver syndrome)
Evaluation of disease mechanism in individuals with rare autosomal recessive disease and only one carrier parent
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 |
Testing Algorithm
Polymerase chain reaction and microsatellite markers on the chromosome of interest are used to test DNA from the parents and the child for the presence of uniparental disomy. Uniparental disomy testing is available for all chromosomes, with the exception of chromosome 11 for certain indications. Contact the laboratory for additional information.
For prenatal specimens only: If amniotic fluid (nonconfluent cultured cells) is received, amniotic fluid culture/genetic test will be added and charged separately. If chorionic villus specimen (nonconfluent cultured cells) is received, fibroblast culture for genetic test will be added and charged separately.
See Prader-Willi and Angelman Syndromes: Laboratory Approach to Diagnosis algorithm in Special Instructions.
Special Instructions
Method Name
Polymerase Chain Reaction (PCR)/Microsatellite markers
Reporting Name
Uniparental DisomySpecimen Type
VariesShipping Instructions
Specimen preferred to arrive within 96 hours of collection.
Specimen Required
For optimal interpretation of results, 3 specimens are required to perform this test. In addition to child or fetal specimen, a blood specimen from both parents is required. Each specimen must have a separate order for Uniparental Disomy (this test). Only the proband specimen will be charged.
Patient Preparation: A previous bone marrow transplant from an allogenic donor will interfere with testing. Call 800-533-1710 for instructions for testing patients who have received a bone marrow transplant.
Submit only 1 of the following specimens:
Specimen Type: Whole blood
Preferred: Lavender top (EDTA) or yellow top (ACD)
Acceptable: Any anticoagulant
Specimen Volume: 3 mL
Collection Instructions:
1. Invert several times to mix blood.
2. Send specimen in original tube.
Specimen Stability Information: Ambient (preferred)/Refrigerated
Prenatal Specimens
Due to the complexity of prenatal testing, consultation with the laboratory is required for all prenatal testing.
Specimen Type: Amniotic fluid
Container/Tube: Amniotic fluid container
Specimen Volume: 20 mL
Specimen Stability Information: Refrigerated (preferred)/Ambient
Specimen Type: Chorionic villi
Container/Tube: 15-mL tube containing 15 mL of transport media
Specimen Volume: 20 mg
Specimen Stability Information: Refrigerated
Acceptable:
Specimen Type: Confluent cultured cells
Container/Tube: T-25 flask
Specimen Volume: 2 Flasks
Collection Instructions: Submit confluent cultured cells from another laboratory.
Specimen Stability Information: Ambient (preferred)/Refrigerated
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 |
Reference Values
An interpretive report will be provided.
Day(s) Performed
Monday and Wednesday
Report Available
5 to 21 daysPerforming Laboratory

Test Classification
This test was developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
81402
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
UNIPD | Uniparental Disomy | 36917-3 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
53356 | Result Summary | 50397-9 |
53357 | Result | 36917-3 |
53358 | Interpretation | 69047-9 |
53359 | Reason for Referral | 42349-1 |
53360 | Specimen | 31208-2 |
53361 | Source | 31208-2 |
53362 | Method | 85069-3 |
53363 | Released By | 18771-6 |
Forms
1. New York Clients-Informed consent is required. Document on the request form or electronic order that a copy is on file. The following documents are available in Special Instructions:
-Informed Consent for Genetic Testing (T576)
-Informed Consent for Genetic Testing-Spanish (T826)
2. Molecular Genetics: Congenital Inherited Diseases Patient Information (T521) in Special Instructions