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

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.

Technical Information

• This test is performed using Multiplex Ligation-dependent Probe Amplification (MLPA).
• MLPA analysis is performed to determine if a copy-number alteration involving one or more exons of the PLP1 gene is present. MLPA is a molecular technique that allows the determination of dosage for specific sequences of interest (Schouten et al. (2002) Nucleic Acids Research 30, e57).
• Probes for all seven PLP1 exons, in combination with a variety of control probes, are analyzed and quantified.

Specimen Requirements

• The preferred sample type is 3-4 ml of peripheral blood collected in an EDTA (purple top) tube. Extracted DNA and saliva are also accepted for this test. Blood and saliva kits are available by request.
• Send approximately 5µg of extracted DNA at a requested concentration of 90-130 ng/µl. Blood and saliva kits are available by request.
• Saliva samples must be submitted in an approved saliva kit.

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.
• Extracted DNA should be sent at room temperature via overnight delivery.
• Saliva is stable at room temperature and can be delivered via overnight or ground shipping.