Reference Interval:
By report
|
| Interpretive Data: |
Background Information:
Characteristics:
Alpha (+) thalassemia (silent carrier): Mutation of a single alpha2 globin gene (-a/aa); asymptomatic. Alpha (0) thalassemia (trait): Mutation of both alpha2 globin genes, or deletion of alpha1 and alpha2 globin genes in cis (-a/-a; --/aa); mild microcytic anemia possible. Hemoglobin H disease: Mutation of three alpha globin genes (--/-a); hemolysis with Heinz bodies, moderate anemia, splenomegaly. Hb Bart Hydrops Fetalis Syndrome: Mutation of four alpha globin genes (--/--); lethal in fetal or early neonatal period.
Incidence: Carrier frequency in Mediterranean (1:30-50), Middle Eastern, Southeast Asian (1:20), African, African-American (1:3).
Inheritance: Autosomal recessive.
Cause: Mutations in the alpha globin gene cluster 95% are deletions.
Mutations Tested: -a3.7, -a4.2, -(a)20.5, --SEA, --MED, --FIL, --THAI
Clinical Sensitivity: Varies by ethnicity, may be as high as 90%.
Methodology: Polymerase chain reaction and gel electrophoresis.
Analytical Sensitivity and Specificity: Greater than 99%
Limitations: Rare alpha globin gene deletions, non-deletion mutations, gene duplications, and mutations of the regulatory region will not be detected.
Please refer to Statement C in the Compliance Statements section in the front of the Laboratory Test Directory.
|
| CPT Code(s): |
83890 Isolation; 83900 Amplification multiplex; 83901 x8 Additional amplification; 83894 Gel separation; 83912 Interpretation and report - Additional CPT code modifiers may be required for procedures performed to test for oncologic or inherited disorders.
|
|
![[ image for: Patient History for Hemoglobinopathy]](icon_39.jpg){kind=icon}