Alpha-Thalassemia X-linked Intellectual Disability (ATR-X) Sequencing
| Disorder | Alpha-thalassemia X-linked Intellectual Disability | |
| Gene Name | ATRX | |
| Clinical info | Alpha-thalassemia X-linked Intellectual Disbility (ATR-X) is an XLID condition caused by mutations in the ATRX/XNP gene localized to Xq13. Males usually present with moderate intellectual disability and characteristic hypotonic facies, consisting of small head size, depressed nasal bridge, large open mouth, large prominent lips and an inverted upper lip. Carrier females exhibit no features, a result of highly skewed X-inactivation. Males can sometimes exhibit hemoglobin H inclusion bodies but this clinical test is unreliable for diagnosis purposes. | |
| 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. | |
| Detection | Sequencing of ATR-X will detect a mutation in 95% of individuals with this disorder. | |
| 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. | |
| Turnaround time | 6 weeks | |
| 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 83898 (x12), 83904 (x10), 83909 (x10) Known mutation 83898, 83904 (x2), 83909 (x2), 83912 |
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| Cost | $2200 for sequencing $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 or This email address is being protected from spambots. You need JavaScript enabled to view it. , DNA Diagnostic Laboratory Coordinator at 1-800-473-9411 | |
Form Needed
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Kellie King, MS, CGC