IFNA16 genetic characterization. (A) Chromosome 9 structure shows JAK2 and IFNA16 genomic regions and SNVs used for association analyses in the P value (−log₁₀) scatter plots (n = 51). Note the stronger association of both IFNA16 SNVs compared with those of JAK2 SNVs. The accompanying linkage disequilibrium heatmap was generated by using pairwise χ² test for 7 evaluable JAK2 SNVs or 5 evaluable IFNA SNVs (3, IFNA16; 1, IFNA17; 1, IFNA5) using the MPN genotyping data. Boxes indicate D values for SNV pairs. (B) Genomic organization of the IFN gene cluster and IFNA16 dideoxy sequence analysis delineating the 3 SNVs and their predicted translation products (all displayed 5′-3′ orientation using RefSeq NM_002173.3 as reference). For all sequences, the polymorphic transition is underscored and delineated by the asterisk. Chromosomal positions are based on National Center for Biotechnology Information Build 37 (GRCh37).