The homozygous state of Hb J Sardegna
| Autor: | Maurizio Roberto Longinotti, Luciana Guiso, Paola Pistidda, Laura Frogheri |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
Male
medicine.medical_specialty Microcytic anemia Thalassemia Biology Gene mapping Pregnancy hemic and lymphatic diseases Internal medicine medicine Humans Gene Genetics Hemoglobin J Hematology Specific mutation Point mutation Homozygote Pregnancy Complications Hematologic beta-Thalassemia Globin chain Anemia medicine.disease Molecular biology Globins Female Polymorphism Restriction Fragment Length |
| Zdroj: | The hematology journal : the official journal of the European Haematology Association. 3(4) |
| ISSN: | 1466-4860 |
| Popis: | Hb J Sardegna is a well known innocent Hb variant which is widespread in Sardinia. As yet, homozygosity for Hb J Sardegna has not been documented. This report deals with the homozygous state for Hb J which we demonstrate by molecular analysis in two Sardinian siblings in which b-thalassemia coexists. The Hb J specific mutation was determined both by enzyme digestion and by sequencing specific segments of PCR amplified a-globin genes. A pregnant girl showed mild non-sideropenic microcytic anemia, normal Hb A2 levels (2.4%) on DE-52 microchromatography, 50% of Hb variant on HPLC and 2.1 a/b globin chain biosynthetic ratio. She proved to be a carrier of the b86(-A) thalassemia determinant. The aglobin gene mapping did not reveal a-thalassemia. Btg I restriction analysis of both a2-globin genes showed a recognition site defect for this enzyme in both chromosomes, which resulted to be the C?A point mutation in homozygosity at the first nt of a2-globin gene 50th codon by sequencing. This defect, typical of Hb J Sardegna, was also present in her brother. From a practical point of view, this study demonstrates that the association of b-thalassemia with Hb J, may show falsely reduced Hb A2 levels on routine Hb A2 quantitation techniques, such as DE-52 microchromatography. This possibility implies that identification methods such as simple Hb electrophoresis, which permit visualization of Hb A J 2 should be used in thalassemia screening involving populations in which Hb J and b-thalassemia coexist. The Hematology Journal (2002) 3, 176‐178. doi:10.1038/sj.thj.6200172 |
| Databáze: | OpenAIRE |
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