Non-S Sickling Hemoglobin Variants: Historical, Genetic, Diagnostic, and Clinical Perspectives
Apart from hemoglobin-S (HbS), there are other Hb variants (non-S sickling Hb variants) that cause sickle cell disease. However, the profiles of these non-S sickling Hb variants have neither been collated nor harmonized. A literature search revealed 14 non-S sickling Hb variants (HbC-Harlem, HbC-Zig...
| Main Authors: | , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Oman Medical Specialty Board
2021-05-01
|
| Series: | Oman Medical Journal |
| Subjects: | |
| Online Access: | http://omjournal.org/articleDetails.aspx?coType=1&aId=2916 |
| _version_ | 1818657549781565440 |
|---|---|
| author | Sagir G. Ahmed Umma A. Ibrahim |
| author_facet | Sagir G. Ahmed Umma A. Ibrahim |
| author_sort | Sagir G. Ahmed |
| collection | DOAJ |
| description | Apart from hemoglobin-S (HbS), there are other Hb variants (non-S sickling Hb variants) that cause sickle cell disease. However, the profiles of these non-S sickling Hb variants have neither been collated nor harmonized. A literature search revealed 14 non-S sickling Hb variants (HbC-Harlem, HbC-Ziguinchor, HbS-Travis, HbS-Antilles, HbS-Providence, HbS-Oman, HbS-Cameroon, HbS-South End, Hb Jamaica Plain, HbC-Ndjamena, HbS-Clichy, HbS-San Martin, HbS-Wake, and HbS-São Paulo). Generally, the non-S sickling Hb variants are double mutants with the HbS mutation (GAG>GTG: βGlu6Val) and additional β-chain mutations. Consequently, non-S sickling Hb variants give positive solubility and sickling tests, but they differ from HbS with respect to stability, oxygen affinity, and electro-chromatographic characteristics. Similarities and discrepancies between HbS and non-S sickling Hb variants create diagnostic pitfalls that can only be resolved by elaborate electro-chromatographic and/or genetic tests. It is therefore imperative that tropical hematologists should have a thorough understanding of these atypical sickling Hb variants. Collated and harmonized appraisal of the non-S sickling Hb variants have not been previously undertaken. Hence, this paper aims to provide a comprehensive but concise historical, genetic, comparative, diagnostic, and clinical overview of non-S sickling Hb variants. The elaborate techniques often required for precise diagnosis of non-S sickling Hb variants are regrettably not readily available in low resource tropical countries, which paradoxically carry the heaviest burden of sickling disorders. We strongly recommend that tropical countries should upgrade their diagnostic laboratory facilities to avoid misdiagnosis of these atypical Hb mutants. |
| first_indexed | 2024-12-17T03:43:15Z |
| format | Article |
| id | doaj.art-8629018ea2084abba039ab39f4f5487e |
| institution | Directory Open Access Journal |
| issn | 1999-768X 2070-5204 |
| language | English |
| last_indexed | 2024-12-17T03:43:15Z |
| publishDate | 2021-05-01 |
| publisher | Oman Medical Specialty Board |
| record_format | Article |
| series | Oman Medical Journal |
| spelling | doaj.art-8629018ea2084abba039ab39f4f5487e2022-12-21T22:04:57ZengOman Medical Specialty BoardOman Medical Journal1999-768X2070-52042021-05-01363e261e26110.5001/omj.2021.102Non-S Sickling Hemoglobin Variants: Historical, Genetic, Diagnostic, and Clinical PerspectivesSagir G. Ahmed0Umma A. Ibrahim1Department of Hematology, Aminu Kano Teaching Hospital, Kano State, NigeriaDepartment of Pediatrics, Aminu Kano Teaching Hospital, Kano State, NigeriaApart from hemoglobin-S (HbS), there are other Hb variants (non-S sickling Hb variants) that cause sickle cell disease. However, the profiles of these non-S sickling Hb variants have neither been collated nor harmonized. A literature search revealed 14 non-S sickling Hb variants (HbC-Harlem, HbC-Ziguinchor, HbS-Travis, HbS-Antilles, HbS-Providence, HbS-Oman, HbS-Cameroon, HbS-South End, Hb Jamaica Plain, HbC-Ndjamena, HbS-Clichy, HbS-San Martin, HbS-Wake, and HbS-São Paulo). Generally, the non-S sickling Hb variants are double mutants with the HbS mutation (GAG>GTG: βGlu6Val) and additional β-chain mutations. Consequently, non-S sickling Hb variants give positive solubility and sickling tests, but they differ from HbS with respect to stability, oxygen affinity, and electro-chromatographic characteristics. Similarities and discrepancies between HbS and non-S sickling Hb variants create diagnostic pitfalls that can only be resolved by elaborate electro-chromatographic and/or genetic tests. It is therefore imperative that tropical hematologists should have a thorough understanding of these atypical sickling Hb variants. Collated and harmonized appraisal of the non-S sickling Hb variants have not been previously undertaken. Hence, this paper aims to provide a comprehensive but concise historical, genetic, comparative, diagnostic, and clinical overview of non-S sickling Hb variants. The elaborate techniques often required for precise diagnosis of non-S sickling Hb variants are regrettably not readily available in low resource tropical countries, which paradoxically carry the heaviest burden of sickling disorders. We strongly recommend that tropical countries should upgrade their diagnostic laboratory facilities to avoid misdiagnosis of these atypical Hb mutants.http://omjournal.org/articleDetails.aspx?coType=1&aId=2916hemoglobinsickleanemiasickle cell |
| spellingShingle | Sagir G. Ahmed Umma A. Ibrahim Non-S Sickling Hemoglobin Variants: Historical, Genetic, Diagnostic, and Clinical Perspectives Oman Medical Journal hemoglobin sickle anemia sickle cell |
| title | Non-S Sickling Hemoglobin Variants: Historical, Genetic, Diagnostic, and Clinical Perspectives |
| title_full | Non-S Sickling Hemoglobin Variants: Historical, Genetic, Diagnostic, and Clinical Perspectives |
| title_fullStr | Non-S Sickling Hemoglobin Variants: Historical, Genetic, Diagnostic, and Clinical Perspectives |
| title_full_unstemmed | Non-S Sickling Hemoglobin Variants: Historical, Genetic, Diagnostic, and Clinical Perspectives |
| title_short | Non-S Sickling Hemoglobin Variants: Historical, Genetic, Diagnostic, and Clinical Perspectives |
| title_sort | non s sickling hemoglobin variants historical genetic diagnostic and clinical perspectives |
| topic | hemoglobin sickle anemia sickle cell |
| url | http://omjournal.org/articleDetails.aspx?coType=1&aId=2916 |
| work_keys_str_mv | AT sagirgahmed nonssicklinghemoglobinvariantshistoricalgeneticdiagnosticandclinicalperspectives AT ummaaibrahim nonssicklinghemoglobinvariantshistoricalgeneticdiagnosticandclinicalperspectives |