Aruna Rangan, Kenneth C. Swanson, Michelle Savedra, Xi Zhang, James D. Hoyer, Jennifer L. Herrick
{"title":"Hb Lepore Rochester-MN,一种新的β - δβ双交叉血红蛋白变体","authors":"Aruna Rangan, Kenneth C. Swanson, Michelle Savedra, Xi Zhang, James D. Hoyer, Jennifer L. Herrick","doi":"10.1016/j.bcmd.2025.102937","DOIUrl":null,"url":null,"abstract":"<div><h3>Introduction</h3><div>The β-globin gene cluster harbors highly homologous globin genes. Crossover events involving the δ <em>(HBD)</em> and β <em>(HBB)</em> genes result in Lepore (δβ) and anti-Lepore (βδ) hemoglobins (Hbs). Recently, double crossover (βδβ) variants have been reported. Herein, we report βδβ variants identified in our laboratory including the novel Hb Lepore Rochester-MN (LRM).</div></div><div><h3>Methods</h3><div>Blood samples were obtained with Institutional Review Board approval. Protein characterization included cation exchange high performance liquid chromatography (HPLC), capillary electrophoresis (CE) and mass spectrometry (MS). Molecular analysis included <em>HBB</em> Sanger sequencing and multiplex ligation-dependent probe amplification (MLPA).</div></div><div><h3>Results</h3><div>Two distinct βδβ crossover variants were identified: Novel Hb LRM (2 infants, 1 adult) and Hb Wanjiang. Hb LRM separated on protein studies (HPLC, CE and MS) and showed identical protein characteristics as Hb Lepore-Hollandia, however, it was expressed at a higher percentage. Sanger sequencing characterized the variant as NM_000518.4(HBB):c.28_68delins41 (p.Ser10_Glu23delins14TAVNALWGKVNVDA). Hb Wanjiang protein did not separate from Hb A using routine methods (HPLC, CE and IEF) but was identifiable by MS and DNA sequencing as NM_000518.4(HBB):c.255_264delinsTTTTTCTCAG (p.A87_T88delinsSQ).</div></div><div><h3>Conclusions</h3><div>The copy neutral incorporation of δ segments into β gene does not worsen the clinical phenotype. Some substitutions may even have a protective effect when coinherited with Hb S. These uncommon double crossover βδβ variants can pose a diagnostic challenge for laboratories as they can be mistaken for other similar variants on protein evaluation. Also, they may require specialized analysis such as MS, Sanger sequencing or NGS. Interpretation can be challenging if comparison to δ-gene is not considered.</div></div>","PeriodicalId":8972,"journal":{"name":"Blood Cells Molecules and Diseases","volume":"113 ","pages":"Article 102937"},"PeriodicalIF":2.1000,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Hb Lepore Rochester-MN, a novel βδβ double crossover hemoglobin variant\",\"authors\":\"Aruna Rangan, Kenneth C. Swanson, Michelle Savedra, Xi Zhang, James D. Hoyer, Jennifer L. Herrick\",\"doi\":\"10.1016/j.bcmd.2025.102937\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><h3>Introduction</h3><div>The β-globin gene cluster harbors highly homologous globin genes. Crossover events involving the δ <em>(HBD)</em> and β <em>(HBB)</em> genes result in Lepore (δβ) and anti-Lepore (βδ) hemoglobins (Hbs). Recently, double crossover (βδβ) variants have been reported. Herein, we report βδβ variants identified in our laboratory including the novel Hb Lepore Rochester-MN (LRM).</div></div><div><h3>Methods</h3><div>Blood samples were obtained with Institutional Review Board approval. Protein characterization included cation exchange high performance liquid chromatography (HPLC), capillary electrophoresis (CE) and mass spectrometry (MS). Molecular analysis included <em>HBB</em> Sanger sequencing and multiplex ligation-dependent probe amplification (MLPA).</div></div><div><h3>Results</h3><div>Two distinct βδβ crossover variants were identified: Novel Hb LRM (2 infants, 1 adult) and Hb Wanjiang. Hb LRM separated on protein studies (HPLC, CE and MS) and showed identical protein characteristics as Hb Lepore-Hollandia, however, it was expressed at a higher percentage. Sanger sequencing characterized the variant as NM_000518.4(HBB):c.28_68delins41 (p.Ser10_Glu23delins14TAVNALWGKVNVDA). Hb Wanjiang protein did not separate from Hb A using routine methods (HPLC, CE and IEF) but was identifiable by MS and DNA sequencing as NM_000518.4(HBB):c.255_264delinsTTTTTCTCAG (p.A87_T88delinsSQ).</div></div><div><h3>Conclusions</h3><div>The copy neutral incorporation of δ segments into β gene does not worsen the clinical phenotype. Some substitutions may even have a protective effect when coinherited with Hb S. These uncommon double crossover βδβ variants can pose a diagnostic challenge for laboratories as they can be mistaken for other similar variants on protein evaluation. Also, they may require specialized analysis such as MS, Sanger sequencing or NGS. Interpretation can be challenging if comparison to δ-gene is not considered.</div></div>\",\"PeriodicalId\":8972,\"journal\":{\"name\":\"Blood Cells Molecules and Diseases\",\"volume\":\"113 \",\"pages\":\"Article 102937\"},\"PeriodicalIF\":2.1000,\"publicationDate\":\"2025-05-23\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Blood Cells Molecules and Diseases\",\"FirstCategoryId\":\"3\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S1079979625000294\",\"RegionNum\":4,\"RegionCategory\":\"医学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"HEMATOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Blood Cells Molecules and Diseases","FirstCategoryId":"3","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1079979625000294","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"HEMATOLOGY","Score":null,"Total":0}
Hb Lepore Rochester-MN, a novel βδβ double crossover hemoglobin variant
Introduction
The β-globin gene cluster harbors highly homologous globin genes. Crossover events involving the δ (HBD) and β (HBB) genes result in Lepore (δβ) and anti-Lepore (βδ) hemoglobins (Hbs). Recently, double crossover (βδβ) variants have been reported. Herein, we report βδβ variants identified in our laboratory including the novel Hb Lepore Rochester-MN (LRM).
Methods
Blood samples were obtained with Institutional Review Board approval. Protein characterization included cation exchange high performance liquid chromatography (HPLC), capillary electrophoresis (CE) and mass spectrometry (MS). Molecular analysis included HBB Sanger sequencing and multiplex ligation-dependent probe amplification (MLPA).
Results
Two distinct βδβ crossover variants were identified: Novel Hb LRM (2 infants, 1 adult) and Hb Wanjiang. Hb LRM separated on protein studies (HPLC, CE and MS) and showed identical protein characteristics as Hb Lepore-Hollandia, however, it was expressed at a higher percentage. Sanger sequencing characterized the variant as NM_000518.4(HBB):c.28_68delins41 (p.Ser10_Glu23delins14TAVNALWGKVNVDA). Hb Wanjiang protein did not separate from Hb A using routine methods (HPLC, CE and IEF) but was identifiable by MS and DNA sequencing as NM_000518.4(HBB):c.255_264delinsTTTTTCTCAG (p.A87_T88delinsSQ).
Conclusions
The copy neutral incorporation of δ segments into β gene does not worsen the clinical phenotype. Some substitutions may even have a protective effect when coinherited with Hb S. These uncommon double crossover βδβ variants can pose a diagnostic challenge for laboratories as they can be mistaken for other similar variants on protein evaluation. Also, they may require specialized analysis such as MS, Sanger sequencing or NGS. Interpretation can be challenging if comparison to δ-gene is not considered.
期刊介绍:
Blood Cells, Molecules & Diseases emphasizes not only blood cells, but also covers the molecular basis of hematologic disease and studies of the diseases themselves. This is an invaluable resource to all those interested in the study of hematology, cell biology, immunology, and human genetics.