Chromosome 7 UPD Analysis

Test Information

Comparative analysis between proband and parental samples for markers on chromsome 7.

Turnaround Time

3 weeks

CPT Code(s)

81402

Cost

$500


Chromosomes

Chromosome 7

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

Maternal UPD of chromosome 7 accounts for about 7-10% of cases of Russell-Silver syndrome.

Specimen Requirements

5 to 7 ml of peripheral blood collected in an EDTA (lavender top) tube is the preferred specimen type. The minimal blood needed for reliable DNA isolation is 3 ml. Extracted DNA, dried blood spots, and saliva are also accepted for this test.

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
Kellie Walden, MS, CGC

Molecular Testing, UPD
One Mother's Story

One Mother's Story

After a long three-year struggle trying to have children, our son, Charlie, was born on April 18, 2009. He was our miracle...perfect in every way! When Charlie was five days old, our pediatrician called to notify us that one of the numbers from the heel prick test was a bit high. We headed to the hospital that afternoon for more tests. I will never forget the following day. It was cool and crisp - not a cloud in the sky....

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