Alpha Thalassemia (HBA1 and HBA2) Deletion/Duplication with reflex to Hb Constant Spring, Fetal
Also known as: HBA DDCSFE
Use
Diagnostic testing for alpha thalassemia in fetuses with suggestive clinical findings or at risk for the disorder due to familial HBA1/HBA2 deletions or the hemoglobin Constant Spring variant. This test detects common, rare, and novel deletions or duplications of the alpha globin gene cluster and the HbCS variant, providing crucial data for prenatal risk assessment and clinical decision-making.
Special Instructions
Informed consent is required for genetic testing, especially for New York patients. Genetic counseling is recommended based on the results. The Fetal Molecular Testing Patient History Form should accompany the order.
Limitations
Diagnostic errors may occur due to rare sequence variations. Specific breakpoints of large deletions/duplications won't be determined, potentially making it difficult to distinguish similar-sized variants. Nondeletional variants within the coding or regulatory regions of the alpha globin cluster genes, except HbCS, will not be detected. Fetuses with both a deletion and duplication may appear to have a normal number of alpha globin gene copies. Rare syndromic or acquired forms of alpha thalassemia associated with ATRX gene variants will not be detected.
New York Approved
Methodology
Other
Biomarkers
LOINC Codes
- 59266-7
- 66746-9
- 55234-9
Result Turnaround Time
9-10 days
Related Documents
For more information, please review the documents below
Specimen
Cultured Cells
Volume
Not provided
Minimum Volume
Not provided
Collection Instructions
Transfer cultured amniocytes or CVS to two T-25 flasks at 80 percent confluence. Backup cultures must be retained at the client's institution until testing is complete. If ARUP receives a sample below the minimum confluence, additional charges may apply.
Storage Instructions
CRITICAL ROOM TEMPERATURE. Must be received within 48 hours of collection due to cell viability.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 48 hours |
| Refrigerated | Unacceptable |
| Frozen | Unacceptable |