General information
Globin chain involved
Status
Heterozygous
Migration zones
Migration positions
214
Sickle Cell Disease: No
Thalassemic variant: No
Capillary Electrophoresis
Fractions
Value %
Hb A
95.8
Hb Ann Arbor
2.0
Hb A2
2.2
Comments
The hyperinstability of the rare variant Hb Ann Arbor leads to the appearance of a small peak in the Z(S) zone.
Mutation data
Heterozygous Hb Ann Arbor
Mutation
HGVS Nomenclature
Alpha2 or Alpha1 80(F1) Leu>Arg
HBA2:c.242T>G (or HBA1)
Hematological parameters
Name
Result
RBC Count
Normal
Total Hemoglobin
Normal
MCV
Low
MCH
Low
Blood smear
No information
Other analysis
Normal hematocrit
Comments on hematology
Normal in plain carrier. Microcytosis, hypochromia and presence of target cells in case of combination with alpha-thalassemia
Clinical context
Clinical presentation
Normal
Clinical risk
Could generate hemolytic anemia in combination with alpha-thalassemia
Variant information
Stability
Unstable
Oxygen affinity
No data
Ethnicities in literature
Found in Caucasian populations: met in a few Caucasian families living in the USA, and in a 33-year-old pregnant woman from the UK
Comments on variant information
There is evidence that the alphaX chain is rapidly catabolized.
Scientific Literature
Scientific references
- https://pubmed.ncbi.nlm.nih.gov/4325866/ Schnitzer B. et al., Science. 1971 Jul 16;173(3993):251-2.
- https://pubmed.ncbi.nlm.nih.gov/5033650/ Adams J.G. 3rd et al., Science. 1972 Jun 30;176(4042):1427-9.
- https://pubmed.ncbi.nlm.nih.gov/4530655/ Adams J.G. 3rd et al., Ann N Y Acad Sci. 1974 Nov 29;241(0):232-41.
- https://pubmed.ncbi.nlm.nih.gov/26635043/ Henderson SJ. et al., Hemoglobin. 2016;40(2):75-84.
Globin Chain involved
Status
The term "Double Heterozygous" refers to cases of heterozygosity on different globin chain types, while the term "Compound Heterozygous" refers to cases of heterozygosity on the same globin chain type.
For example, S/G-Pest is a Double Heterozygous case (beta and alpha-globin chains are mutated) and S/C is a Compound Heterozygous case (only beta-globin chains are mutated).
Migration zones
Migration positions
In some cases (homozygotes, combination of the variant with thalassemia, transfused patients, degraded samples or unstable variants), the variation in the migration position may be greater than +/- 1 point.
For profiles with thalassemia, only Hb A2 and Hb F peaks, if present, are listed with migration positions.
Sickle Cell Disease
Thalassemic variant
Capillary Electrophoresis
Variant information
Ethnicities are provided for informational purposes only and are based on scientific literature and conference posters.
A hemoglobin variant may therefore be present in populations of ethnic origins or countries not listed here.
Hematological Parameters