Chromosome 15 UPD Analysis

Test Information

Comparative analysis between proband and parental samples for markers on chromsome 15.

Turnaround Time

3 weeks

CPT Code(s)

81402

Cost

$500


Chromosomes

Chromosome 15

Clinical Information

Uniparental disomy describes the abnormal assortment of chromosomes from parent to child. Normally, one-half of the genetic material is derived from each parent. In uniparental disomy, the chromosome number is correct, but both members of a chromosome pair or segments of a chromosome pair are inherited from the same parent. The detection of uniparental disomy involves PCR analysis of genetic material from the affected child and both parents.

Indications

UPD testing is useful to confirm the diagnosis and to identify the etiology of the disorder within a family as well as to establish the inheritance of Robertsonian translocations.

Detection

UPD causes approximately 25% of cases of Prader-Willi syndrome and approximately 7% of cases of Angelman syndrome. Segmental UPD may not be detected. Please provide coordinates prior to sending the sample for any region with absence of heterozygosity (AOH) to confirm that we have markers to cover the region of interest.

Specimen Requirements

The preferred sample type is 3-5 ml of peripheral blood collected in an EDTA (purple top) tube. Extracted DNA, dried blood spots, and saliva are also accepted for this test. Saliva samples must be submitted in an approved saliva kit. Contact the lab to receive a saliva kit or to have one sent to your patient. This test requires a sample on the proband and both parents for complete analysis.

Transport Instructions

The specimen should be kept at room temperature and delivered via overnight shipping. If shipment is delayed by one or two days, the specimen should be refrigerated and shipped at room temperature. Do not freeze the specimen. Samples collected on Friday can be safely designated for Monday delivery.

Prenatal Testing Information

Prenatal diagnosis is available if there is a translocation in a parent and/or the fetus increasing the risk for UPD. The cost of prenatal diagnosis is different than a postnatal sample. In addition, there may be extra costs associated with cell culture and maternal cell contamination. Maternal cell contamination studies are required for all prenatal molecular tests. Contact the laboratory prior to sending a prenatal specimen.

Have Questions? Need Support?

Call our laboratory at 1-800-473-9411 or contact one of our Laboratory Genetic Counselors for assistance.
Robin Fletcher, MS, CGC
Falecia Thomas, MS, CGC

Three boys and their dad

Meet the Shorter Boys

Unexpected. If there is a term that sums up life it could very well be: unexpected. Life is full of unexpected moments. Some of these moments can be full of unexpected blessings while others may be full of unexpected obstacles. However, sometimes the unexpected can be both an obstacle and blessing at the same time; you just need someone to help you see both sides. The Greenwood Genetic Center is a place that helps shed some light on the unexpected ...

In The News