Genomic structure of the AHSP gene and its single nucleotide polymorphisms (SNPs). The AHSP gene is located on chromosome 16 (Genbank accession number AC106 730.2), and the figure demonstrates the genomic structure of this gene containing 3 exons (black boxes). Five polymorphic sites (4 SNPs and one (T)_n repeat) were identified, and these allow the construction of 2 major haplotypes, I and II. The minor haplotype Ia is similar to haplotype I for the T repeats¹⁸  and other SNPs except an A/G polymorphism in the intervening sequence (IVS) I (coordinate number 12 347 according to Genbank accession number AC106 730.2). Approximately 1.4 kb of the AHSP gene (shaded box) was sequenced in 50 individuals with Hb E/β thalassemia.