Coffin-Lowry Syndrome: RPS6KA3 Sequencing

Turnaround Time

6 weeks

CPT Code(s)

81479

Cost

$1,500

Genes

• Coffin-Lowry syndrome

Coffin-Lowry syndrome is an X-linked intellectual disability condition caused by mutations in the protein kinase gene, RPS6KA3, localized to Xp22. Males present with moderate to severe developmental delay, coarse facies, large soft hands with short tapering fingers, hypotonia, joint hyperextensibility and skeletal changes. Carrier females have mild intellectual impairment and short stature, coarse face, prominent lips, soft fleshy hands with thick tapering fingers. Decreased levels of ribosomal S6 kinase activity can be observed in white cells but usually only after establishing a cell line.

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.

Sanger Sequencing

A mutation in RPS6KA3 will be indentified in approximately 90-95% of patients with Coffin-Lowry syndrome.

The preferred sample type is 3-5 ml of peripheral blood collected in an EDTA (purple top) tube. 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.

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 diagnosis is available if the familial mutations are 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.