Table 6.

Sickle Cell Disease: Typical Proband and Parent Hemoglobin Alleles

Hemoglobin Beta Chain Variants in ProbandTypical Parental Hemoglobin Alleles 1
One ParentOther Parent
Hb S/SA/SA/S
Hb S/β0-thal 2A (w/additional laboratory features of β0-thal or β+-thal carrier: ↓ MCV, normal or ↑ HbA2, normal or ↑ HbF)
Hb S/β+-thal 2
Hb S/CA/C

Table shows typical results; exceptions occur. Some rare beta globin chain variants (e.g., Hb S/D, Hb S/E, Hb S/O) are not included.

Hb = hemoglobin; HbA = adult hemoglobin; HbF = fetal hemoglobin; Hb S/C = sickle-hemoglobin C disease; Hb S/S = homozygous for HBB variant p.Glu6Val; MCV = mean corpuscular volume; thal = thalassemia; ↑ = increased; ↓ = decreased

1.

Assumes that uniparental disomy is absent and that both parents are heterozygous. Some parents may be homozygous or compound heterozygous.

2.

HbA is detectable in individuals with Hb S/β+-thalassemia but not Hb S/β0-thalassemia or Hb S/C.

From: Sickle Cell Disease

Cover of GeneReviews®
GeneReviews® [Internet].
Adam MP, Feldman J, Mirzaa GM, et al., editors.
Seattle (WA): University of Washington, Seattle; 1993-2024.
Copyright © 1993-2024, University of Washington, Seattle. GeneReviews is a registered trademark of the University of Washington, Seattle. All rights reserved.

GeneReviews® chapters are owned by the University of Washington. Permission is hereby granted to reproduce, distribute, and translate copies of content materials for noncommercial research purposes only, provided that (i) credit for source (http://www.genereviews.org/) and copyright (© 1993-2024 University of Washington) are included with each copy; (ii) a link to the original material is provided whenever the material is published elsewhere on the Web; and (iii) reproducers, distributors, and/or translators comply with the GeneReviews® Copyright Notice and Usage Disclaimer. No further modifications are allowed. For clarity, excerpts of GeneReviews chapters for use in lab reports and clinic notes are a permitted use.

For more information, see the GeneReviews® Copyright Notice and Usage Disclaimer.

For questions regarding permissions or whether a specified use is allowed, contact: ude.wu@tssamda.

NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.