Ten Years of Routine α- and β-Globin Gene Sequencing in UK Hemoglobinopathy Referrals Reveals 60 Novel Mutations

Abstract

We review and report here the genotypes and phenotypes of 60 novel thalassemia and abnormal hemoglobin (Hb) mutations discovered following the adoption of routine DNA sequencing of both α- and β-globin genes for all UK hemoglobinopathy samples referred for molecular investigation. This screening strategy over the last 10 years has revealed a total of 11 new β chain variants, 15 α chain variants, 19 β-thalassemia (β-thal) mutations and 15 α⁺-thalassemia (α⁺-thal) mutations. The large number of new thalassemia alleles confirms the wide racial heterogeneity of mutations in the UK immigrant population. Eleven of the new variants ran with Hb A on high performance liquid chromatography (HPLC), demonstrating the value of routine sequencing of both α- and β-globin genes for all hemoglobinopathy investigations.

The new β chain variants are: Hb Bury [β22(B4)Glu  →  Asp (HBB: c.69A > T)], Hb Fulwood [β35(C1)Tyr → His (HBB: c.106T > C)], Hb Little Venice [β42(CD1)Phe → Cys (HBB: c.128T > G)], Hb Cork [β57(E1)Asn → Ser (HBB: c.173A > G), Hb Basingstoke [β118(GH1)Phe → Ser (HBB: c.356T > C)], Hb Howden [β20(B2)Val → Ala (HBB: c.62T > C)], Hb Wilton [β41(C7)Phe → Leu (HBB: c.126C > A)], Hb Belsize Park [β120(GH3)Lys → Asn (HBB: c.363A > T)], Hb Hampstead Heath [β2(NA2)His → Gln;β26(B8)Glu → Lys (HBB: c.[6C > G;79G > A])], Hb Grantham [β85(F1)Phe → Cys (HBB: c.257T > G)] and Hb Calgary [β64(E8)Gly → Val (HBB: c.194G > T).

The new α chain variants are: Hb Edinburgh [α70(E19)Val → Gly (HBA2: c.212T > G)], Hb Walsgrave [α116(GH4)Glu → Val (HBA2: c.350A > T)], Hb Wexham [α117(GH5) and 118(H1) insertion Ser (HBA1: c.354-355insTCA)], Hb Coombe Park [α127(H10)Lys → Glu (HBA2: c.382A > G)], Hb Oxford [α17(A15)Val → Asp (HBA2: c.53T > A)], Hb Bridlington [α32(B13)Met → Thr (HBA1: c.98T > C), Hb Wolverhampton [α81(F2)Ser → Tyr (HBA2: c.9245C > A)], Hb Little Waltham [α13(A11)Ala → Asp (HBA2: c.41C > A)], Hb Derby [α61(E10)Lys → Arg (HBA1: c.185A > G)], Hb Uttoxter [α74(EF3)Tyr → Asp (HBA2: c.223G > T)], Hb Harehills [α124(H7)Ser → Cys (HBA1: c.374C > G)], Hb Hekinan II [α27(B8)Glu → Asp (HBA1: c.84G > T)], Hb Manitoba IV [α102(G9)Ser → Arg (HBA1: c.307A > C), Hb Witham [α139(HC1)Lys → Arg (HBA2: c.419A > G) and Hb Farnborough [α9(A7)Asn → Asp (HBA1: c.28A > G). In addition, 10 more paralogous α-globin chain variants have been discovered.

The novel β-thal alleles are: HBB: c.-138C > G, HBB: c.-121C > T, HBB: c.-80T > G, HBB: c.18_19delTG, HBB: c.219_220insT, HBB: c.315 + 2_315 + 13delTGAGTCTATGGG, HBB: c.316-70C > G, HBB: c.345_346insTGTGCTG, HBB: c.354delC, HBB: c.376-381delCCAGTG, HBB: c.393T > A, HBB: c.394_395insA, HBB: c.375_376insA, HBB: c.*+95_*+107delTGGATTCTinsC, HBB: c.* + 111_*+112delAA, HBB: c.*+112A > T, HBB: c.394C > T, HBB: c.271delG and HBB: c.316-3C > T.

The novel α ⁺-thal alleles are: HBA1: c.95+1G > C, HBA1: c.315C > G [Hb Donnington, α104(G11)Cys → Trp], HBA1: c.327delC, HBA1: c.333_345del, HBA1: c.*+96G > A, HBA2: c.2T > G, HBA2: c.112delC, HBA2: c.143delA, HBA2: c.143_146delACCT, HBA2: c.156_157insG, HBA2: c.220_223delGTGG, HBA2: c.305T > C [Hb Bishopstown, α101(G8)Leu → His], HBA2: c.169_170delAA, HBA2: c.1A > T and HBA2: c.-3delA.

• α-Thalassemia (α-thal)
• β-thalassemia (β-thal)
• hemoglobin (Hb) variants
• novel mutations
• sequencing

Acknowledgments

The authors wish to acknowledge all the hospital hematology departments and institutions that referred the blood samples for this study, in particular: Donnington Health Centre, Oxford; Manchester Royal Infirmary and North Manchester General Hospital, Manchester; The Calderdale Royal Hospital, Salterhebble; University Hospital Aintree National Health Service (NHS) Trust, Liverpool; St. James’s University Hospital, Leeds; Nobles Hospital, Isle of Man; Cork University Hospital, Cork; Birmingham Children’s Hospital and Birmingham Women’s Hospital, Birmingham; Yorkhill Hospital, Glasgow; Bristol Royal Hospital for Sick Children, Bristol; Scunthorpe General District Hospital, Scunthorpe; University Hospitals of Coventry and Walsgrave, Coventry; The Adelaide and Meath Hospital, Dublin; Whittington, Royal Free, St. Mary’s and St. George’s Hospitals, London; Ninewells Hospital, Dundee; Western General Hospital and Edinburgh Royal Infirmary, Edinburgh; North Hampshire Hospital, Basingstoke; Grantham and District Hospital, Grantham; St. John’s Hospital at Lowden, Livingstone; Bury General Hospital, Bury; Royal Preston Hospital, Preston; Broomfield Hospital, Chelmsford; New Cross Hospital, Wolverhampton; Wexham Park Hospital, Slough.

Declaration of interest

Part of this study has been supported by the European Commission grant for the project “e-Infrastructure for Thalassemia Research Network,” Co-ordination Action, ITHANET, RI-2004-026539, and also by the Oxford Partnership Comprehensive Biomedical Research Centre with funding from the Department of Health’s NIHR Biomedical Research Centres funding scheme. The views expressed in this publication are those of the authors and not necessarily those of the Department of Health. The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.