HBB Deletion/Duplication Analysis

Casandra

Casandra Test Code LC83693Version 1 (DRAFT)

Performing Lab

Lab LabcorpLab Test ID 252240

HBB Deletion/Duplication Analysis

Clinical Use

Use

HBB deletion/duplication analysis is intended for individuals who have a clinical diagnosis of β-thalassemia and have either one or no pathogenic variants detected by HBB full gene sequencing. This test may also be used for carrier screening in individuals at increased risk of being an HBB carrier but have tested negative by HBB full gene sequencing. If testing is needed for a known familial large deletion or duplication, please submit a copy of the laboratory report documenting the familial variant in the index family member.

Special Instructions

Full HBB gene sequencing is required before deletion/duplication analysis can be performed. If testing is needed for a known familial large deletion or duplication, a copy of the laboratory report documenting the familial variant in the index family member should be submitted.

Limitations

The MLPA assay is designed to detect single exon, multi-exon, and full gene deletions or duplications. However, it may not detect certain genomic rearrangements such as translocations, inversions, mosaic variants, or partial exon rearrangements. The assay cannot determine exact breakpoints of deletions or duplications and cannot detect point mutations in the HBB gene. Diagnostic errors may occur due to rare sequence variations.

Test Details