Hemoglobin S/hemoglobin Osler: A case with 3 β globin chains. DNA sequence (AAT) proves that Hb Osler is β 145 Tyr→Asn
✍ Scribed by Hutt, P. Jesse; Donaldson, Milton H.; Khatri, Jamil; Fairbanks, Virgil F.; Hoyer, James D.; Thibodeau, Stephen N.; Moxness, Michael S.; McMorrow, Lydia E.; Green, Michael M.; Jones, Richard T.
- Book ID
- 102646580
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 876 KB
- Volume
- 52
- Category
- Article
- ISSN
- 0361-8609
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✦ Synopsis
A 13-year-old African-American female with erythrocytosis and three different p globins on electrophoresis PA, ps, and po*'er, raised the possibility that one chromosome 11 might contain a duplicated p globin gene, since there are normally only 2 p globin genes. DNA sequence analysis showed GTG at codon 6 in exon 1, corresponding to Hb S and AAT at codon 145 in exon 3, indicating a substitution of Asn for Tyr. Thus, Hb Osler undergoes spontaneous post-translational deamidation, p 145 Asn-p 145 Asp. Unmodified Hb Osler (Asn) co-migrates with Hb A on electrophoresis and co-elutes with Hb A on HPLC; therefore it has not been identified previously. All previous studies have incorrectly identified the mutation as being p 145 (HC 2) Tyr+Asp.