Sequence analysis of HSPA1A and HSPA1B in a multi-ethnic study population

Two copies of the Hsp70 gene, HSPA1A and HSPA1B, are located on chromosome 6p21. The coding regions of HSPA1A and HSPAIB are intronless and nearly identical, however, promoter and 3′ UTR sequences are different. The coding regions and putative promoter regions of HSPAIA and HSPAIB were re-sequenced in an affected and unaffected asthma screening panel of US Caucasians, African Americans, and US Hispanics (n = 72) to identify polymorphisms. HSPAIA and HSPAIB were each amplified in two separate whole-gene fragments. The polymorphisms identified were compared to those reported in dbSNP. Nine polymorphisms (one novel) were identified in HSPAIA, five of which are coding. Fourteen polymorphisms (five novel) were identified in HSPAIB, five of which are coding. One polymorphism (Asp110Glu GAG > GAC) was found in both genes. Two-thirds of the polymorphisms reported in dbSNP were not identified in our screening panel. Although similar in sequence, HSPAIA and HSPAIB do not share common patterns of polymorphisms.