Pelizaeus-Merzbacher Disease (PLP1 Sequencing and MLPA)

Disorders Pelizaeus-Merzbacher Disease, Spastic paraplegia 2
Gene Name PLP1
Clinical info

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 mutation within a family to allow for carrier testing and prenatal diagnosis.
Associated Tests

The PLP1 gene is also included as a part of the 92-gene X-Linked Intellectual Disability panel.

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 10 ml of peripheral blood collected in an EDTA (lavender top) Vacutainer tube is preferred. The minimal blood needed for reliable DNA isolation is 3 ml.
Transport The specimen should be kept at room temperature and delivered via overnight shipping.  FedEx is preferred.  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.
Turnaround time

Sequencing: 6 weeks
MLPA:          2 weeks

Prenatal testing Prenatal diagnosis is available if the familial mutation is 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.
CPT Codes

Unknown mutation
81479

Known mutation
81479

Deletion/Duplication (MLPA)
81406

Cost $700 for sequencing
$350 for known mutation
$500 for MLPA

Prenatal diagnosis for a known mutation is $1000.  Please contact the lab for more information.
Contact For further information contact This email address is being protected from spambots. You need JavaScript enabled to view it. , MS, Lab Counselor at 1-800-473-9411.

Molecular Diagnostic Lab

The Molecular Diagnostic Lab offers DNA analysis for many genetic disorders via gene sequencing, targeted mutation analysis, MLPA deletion/duplication testing, trinucleotide repeat analysis and next generation sequencing panels.

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