Using DNA testing for the precise, definite, and low-cost diagnosis of sickle cell disease and other Haemoglobinopathies: findings from Tanzania

BMC Genomics

Adam Burns¹  Julie Makani²  Heavenlight Christopher²  Emmanuel Josephat²  Siana Nkya³  Anna Schuh⁴ 

[1] Oxford Molecular Diagnostics Centre, University of Oxford, Oxford, UK;Sickle cell programme, Department of haematology and Blood Transfusion, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania;Sickle cell programme, Department of haematology and Blood Transfusion, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania;Department of Biological Sciences, Dar es Salaam University College of Education (DUCE), Dar es Salaam, Tanzania;Sickle cell programme, Department of haematology and Blood Transfusion, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania;Oxford Molecular Diagnostics Centre, University of Oxford, Oxford, UK;

关键词: Comprehensive care;    Newborn screening;    Sickle cell disease;    Haemoglobinopathies;    Nanopore;    DNA sequencing;   

DOI  :  10.1186/s12864-021-08220-x

来源: Springer

【 摘 要 】

BackgroundSickle cell disease (SCD) is an important cause of under-five mortality. Tanzania is the 5th country in the world with the highest births prevalence of SCD individuals. Significant advances in the neonatal diagnosis of SCD using rapid point-of-care testing have been made. However genetic confirmation is still required for positive cases, in uncertain cases, in multiply transfused patients, to resolve compound heterozygosity (Hb S/ β0 Thal or Hb S/ β+ thal) not uncommon in the coastal regions of East Africa and increasingly also for pre-marital counselling and potentially for future curative approaches such as gene therapy. The currently available DNA tests are prohibitively expensive. Here, we describe an easy-to-use, affordable and accurate β-globin sequencing approach that can be easily integrated within existing NBS for SCD and other haemoglobinopathies especially in Low- and Middle-income Countries.AimTo evaluate an affordable DNA technology for the diagnosis of Sickle cell disease and other haemoglobinopathies in a resource-limited setting.MethodsLaboratory-based validation study was conducted by Muhimbili University of Health and Allied Sciences and the University of Oxford involving sequencing of the entire β -haemoglobin locus using the Oxford Nanopore MinION platform. A total number of 36 Dried blood spots and whole blood samples were subjected to conventional protein-based methods (isoelectric focusing, HPLC), and/or sequenced by the Sanger method as comparators.ResultsSequencing results for SCD using the MinION were 100% concordant with those from the Sanger method. In addition, the long-read DNA sequencing method enabled the resolution of cases with unusual phenotypes which make up 1% of all children in Tanzania. The cost is £11/ sample for consumables, which is cheaper compared to other sequencing platforms.ConclusionsThis is the first report of a comprehensive single DNA assay as a definitive diagnostic test for SCD and other haemoglobinopathies. The test is fast, precise, accurate and affordable.

【 授权许可】

CC BY