#ExistRefRange>Normal: This specimen has a normal sequence of the b-globin gene. No mutations were identified within the b-globin coding region, the intron/exon splice site boundaries or intronic positions IVS-II 654, IVS-II 705, and IVS-II 745. Gene deletions or mutations causing thalassemias or hemoglobinopathies outside of these regions will not be identified.
Characteristics: Mutations can result in β+ or β thalassemias (insufficient or absent beta chain production, respectively) as well as structural hemoglobinopathies.
Incidence: Varies with ethnicity.
Inheritance: Usually autosomal recessive, infrequently autosomal dominant.
Cause: Mutations in the HBB gene.
Mutations tested: The complete protein coding sequence with exon/intron boundaries, proximal promoter, 5' and 3' untranslated regions, and intronic mutations IVS-II-654, IVS-II-705 and IVS-II-745 and the 619del common in the Asian Indian population.
Clinical Sensitivity: Up to 97%, depending upon ethnicity.
Methodology: PCR amplification followed by bidirectional sequencing. For 619del, PCR followed by gel electrophoresis.
Analytical sensitivity: 99%
Limitations: Specificity may be compromised by rare primer site mutations. Large-scale deletions or mutations in distal regulatory elements, such as the locus control region, will not be detected.
This test is performed pursuant to an agreement with Roche Molecular Systems, Inc.
Counseling and informed consent are recommended for genetic testing. Consent forms are available online at www.aruplab.com.
See Compliance Statement C: www.aruplab.com/CS
||Beta Thalassemia (Beta Globin (HBB) Sequenicng)