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

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 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 Makayla Gunn

Meet Makayla Gunn

Makayla was diagnosed with Rett Syndrome in April of 2015 at the age of two.   At about 18 months, we noticed she had started some repetitive hand motions, and her pediatrician was a little concerned that she did not have many words.  She had learned some sign language, and was saying ‘mama’ and ‘dada’, but that was it.  Then she suddenly stopped all of that.  At her 2 year old check-up, the pediatrician referred us to BabyNet, ...

In The News