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See Table A. Genes and Databases for chromosome locus and protein.

See Molecular Genetics for information on variants detected in this gene.

Sequence analysis detects variants that are benign, likely benign, of uncertain significance, likely pathogenic, or pathogenic. Variants may include missense, nonsense, and splice site variants and small intragenic deletions/insertions; typically, exon or whole-gene deletions/duplications are not detected. For issues to consider in interpretation of sequence analysis results, click here.

Note: All affected individuals have at least one copy of the p.Glu6Val allele. Targeted assays for p.Glu6Val (HbS), p.Glu6Lys (HbC), p.Glu121Gln (HbD), p.Glu26Lys (HbE), and p.Glu121Lys (HbO_Arab) may be available (see Molecular Genetics).

Gene-targeted deletion/duplication analysis detects intragenic deletions or duplications. Methods used may include a range of techniques such as quantitative PCR, long-range PCR, multiplex ligation-dependent probe amplification (MLPA), and a gene-targeted microarray designed to detect single-exon deletions or duplications.

HBB deletions or duplications will not result in a sickle pathogenic variant; however, HBB deletions are causative of beta-thalassemia, and HBB variant p.Glu6Val in trans with an HBB deletion leads to Hb S/β⁰-thalassemia.