X-Linked Hydrocephalus : L1CAM Sequencing

Test Information

L1CAM sequencing is a molecular test used to identify variants in the gene associated with X-Linked Hydrocephalus.

Turnaround Time

6 weeks

CPT Code(s)

81407

Cost

$1,500

Genes

Clinical Information

L1CAM is associated with a phenotype spectrum including X-linked hydrocephalus, MASA (intellectual disability, aphasia, spastic paraplegia and adducted thumbs), X-linked complicated hereditary spastic paraplegia type 1 (SPG1) and X-linked agenesis of the corpus callosum. The gene encodes for neuronal L1 cell adhesion molecules in the central and peripheral nervous systems, and has been localized to Xq28.

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

Sanger Sequencing

Specimen Requirements

The preferred sample type is peripheral blood collected in an EDTA (purple top) tube – at least 2-3ml for pediatric patients and 5-6ml for adult patients. Extracted DNA, dried blood spots, and saliva are also accepted for this test. Saliva samples must be submitted in an approved saliva kit. Contact the lab to receive a saliva kit or to have one sent to your patient.

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 mutation is known. Prenatal diagnosis can also be requested when there are ultrasound findings suggestive of an L1CAM mutation. 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

Molecular Testing, Sanger Sequencing
Meet Reggie Roper

Meet Reggie Roper

Reggie has been part of the GGC family for over 18 years. He has short stature, webbing of his hands, pulmonary stenosis, seizures and hydrocephalus along with developmental delay. He carried an initial diagnosis of cardiofaciocutaneous (CFC) syndrome; however, as genetic testing advanced, GGC made the diagnosis of Noonan-like syndrome with loose anagen hair by identifying a mutation in the SHOC2 gene. He is also an active participant in the Greenwood Community Theatre's Penguin Project. "GGC is...

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