All PCR primers and allele-specific primers for the multiplex primer
extension genotyping reactions used in this study were designed insilico
using PrimerPremier 5 and PrimerPlex 2 software (Premier Biosoft
International, Palo Alto, CA). Since α-chain haemoglobin (Hb) mutations
can be located in either HBA1 and/or HBA2 genes (NG_000006),
two different primer pairs were used to selectively amplify each of the
highly homologous HBA1 and HBA2 genes. The amplified HBA1 and
HBA2 gene fragments (1087 bp) flanking all 13 mutations were subsequently
used as templates for genotyping by primer extension reaction
in the presence of allele-specific primers. Oligonucleotides used as
primers and probes in the course of this study were synthesized by VBC Genomics (Wien, Austria). HBA1 and HBA2 gene allele-specific
primer sequences are available on request to the authors.