Pelizaeus-Merzbacher Disease, Spastic Paraplegia : PLP1 Deletion/Duplication (MLPA)

Test Information

PLP1 Deletion/Duplication (MLPA) is a molecular test used to detect deletions and duplications in the gene associated with Pelizaeus-Merzbacher Disease, Spastic Paraplegia.

Turnaround Time

2 weeks

CPT Code(s)

81404

Cost

$500

Genes

Clinical Information

Pelizaeus-Merzbacher is an X-linked hypomyelinative leukodystrophy and progressive neurologic condition presenting in infancy. Typical findings include abnormal eye movement, hypotonia, head tremor, ataxia, spasticity, quadri- and paraplegia, involuntary movements and cognitive deficiencies.

Carrier females are usually asymptomatic or may have mild neurologic findings in adulthood, but some severely affected females have been reported as well.

Indications

Molecular testing is useful to confirm the diagnosis and to identify the disease causing mutations within a family to allow for carrier testing and prenatal diagnosis.

Methodology

multiplex ligation-dependent probe amplification (MLPA)

Detection

Sequencing of the PLP1 gene will detect a mutation in approximately 15-25% of affected males. 50-60% of males will have dosage alterations detected by MLPA anlaysis. The majority of these are duplications rather than deletions.

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 the familial mutations are known. Additional fees for cell culture and maternal cell contamination may apply. 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

Deletion/Duplication
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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