Single tube allele specific PCR: a low cost technique for molecular screening of sickle cell anaemia in Nigeria

BACKGROUND: Sickle cell anaemia (SCA) is a hereditary blood disorder caused by a single mutation in the haemoglobin gene. The disease burden of SCA is highest in Nigeria. The allele specific polymerase chain reaction (ASPCR) method is applicable for the direct detection of known single nucleotide polymorphisms (SNPs). OBJECTIVE: To investigate the use of the single tube ASPCR as an accurate and affordable method for SCA screening in Nigeria. METHODS: DNA was extracted from study subjects with normal haemoglobin, HbAA (20), sickle cell anaemia, HbSS (20) and carriers, HbAS (1). Haemoglobin was genotyped by ASPCR using two primer sets that amplifies the wildtype and mutant haemoglobins in each sample. Amplicon sizes were analyzed by gel electrophoresis. RESULTS: Amplicons were visible after electrophoresis at regions 517 base pair (bp) for HbA and 267 bp for HbS. ASPCR correctly and unambiguously detected the presence or absence of haemoglobins A and S from all samples collected, demonstrating its accuracy and precision for the screening of SCA. CONCLUSION: This study validates ASPCR as an effective, low cost approach for the clinical screening of SCA in Nigeria. ASPCR is also applicable for other genetic diseases, paternity testing, and forensics where more expensive fluorescence-based approaches are not obtainable.