Genotyping consists of (i) PCR amplification of a 1087 bp HBA1 gene
fragment (Gene Bank Accession Number NG_000006.1) flanking the
nondeletion mutations in HBA1 gene, (ii) a 10-plex PEXT reaction of
unpurified PCR product in the presence of allele-specific primers (two
primers per mutation, one for the wild type and the second for the
variant allele) and biotin-modified nucleotide and (iii) visual detection
of the PEXT products by multi-allele dipstick type biosensor. HBA1 and
HBA2 gene allele-specific primer sequences are available on request to
the authors.