Costello Syndrome – Tiered Molecular Testing
| Disorder | Costello syndrome | |
| Gene Names | Tier 1: HRAS – first coding exon Tier 2: HRAS – remaining exons including both splice variants for exon 4 Full Panel: Tiers 1 and 2 |
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| Clinical info | Costello syndrome is characterized by intellectual disability, 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. | |
| Indications | Tiers may be ordered separately or can be run as a concurrent panel. If you are requesting multiple tiers, but would like each run separately, please indicate the order if which testing should be done. Molecular testing is useful to confirm the diagnosis and to identify the disease causing mutation within a family to allow for carrier testing and prenatal diagnosis. | |
| Associated Tests | 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. | |
| Detection | 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). | |
| 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 | |
| Transport | 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. | |
| Turnaround time | Tier 1: 2 weeks Tier 2: 6 weeks |
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| Prenatal testing | Prenatal diagnosis is available if the familial mutation is 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. | |
| CPT Codes | Unknown mutation Tier 1: 81403 Tier 2: 81479 Full Panel (Tier 1 and 2 run simultaneously): 81404 Known mutation 81403 |
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| Cost | $300 for Tier 1 $400 for Tier 2 $700 for Full Panel $350 for known mutation |
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| Contact | For further information contact This email address is being protected from spambots. You need JavaScript enabled to view it. , MS, Lab Counselor at 1-800-473-9411. | |
Form Needed
Download molecular-lab-request-form.pdf
Have Questions Need Support?
Contact our Laboratory Representative for assistance.
Kellie King, MS, CGC
Molecular Diagnostic Lab
The Molecular Diagnostic Lab offers DNA analysis for many genetic disorders via gene sequencing, targeted mutation analysis, MLPA deletion/duplication testing, trinucleotide repeat analysis and next generation sequencing panels.