Pelizaeus-Merzbacher Disease (PLP1 Sequencing and MLPA)
|Disorders||Pelizaeus-Merzbacher Disease, Spastic paraplegia 2|
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.|
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.|
Sequencing: 6 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.|
|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.
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.