Costello Syndrome

(Lab studies request form) | CPT Codes/Price List (PDF)

Costello syndrome is characterized by mental retardation, coarse facial features, feeding difficulties, failure to thrive, loose fold of skin (especially on the hands and feet), joint flexibility, short stature, cardiac anomalies and papilomas around the mouth, nose and perianal regions.

Costello syndrome is caused by mutations within the HRAS gene with approximately 80-90% of mutations found in the first coding exon (often called exon 2 in the literature). The Molecular Diagnostic Laboratory of the Greenwood Genetic Center is offering a tiered approach to the molecular diagnosis of Costello syndrome. Tier 1 includes sequencing of the first coding exon of HRAS. Tier 2 allows for sequencing of the remaining exons including both splice variants for exon 4. These tiers may be ordered separately or can be run simultaneously.

The features of Costello syndrome are often found to overlap with those of Noonan syndrome and cardio-facio-cutaneous (CFC) syndrome. Tiered analyses for each of those conditions is also available from the Greenwood Genetic Center.

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. If necessary, ACD solution A Vacutainer tubes (yellow top) may be submitted. Please contact the laboratory for more information.

Transport: Please contact the Molecular Diagnostic Lab Coordinator (1-800-473-9411) for shipping information. 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.

Analysis standards: Analysis will be complete within 6 weeks of sample receipt. The laboratory director and technical staff members independently assess the quality and interpretation of the test. The Greenwood Genetic Center Molecular Diagnostic Laboratory is CLIA certified and actively participates in CAP proficiency surveys.

Reporting of Test Results: Test results with interpretation will be mailed and/or faxed following completion of the test. Verbal reports will be telephoned to the person(s) requesting the test when an abnormal test result occurs. Consultation with the laboratory director and explanations of testing protocols are available upon request.

CPT Codes:

Tier 1: 83890, 83898, 83904, 83909, 83912
Tier 2: 83890, 83898, 83904 (x3), 83909, 83912
Panel (Tier 1 and 2 run simultaneously): 83890, 83898 (x3), 83904 (x5), 83909, 83912