title: HSP70 (HSPA1) polymorphisms in former workers with chronic mercury vapor exposure.
abstract: OBJECTIVE
  To investigate 4 loci of 3 HSP70 genes in caustic soda production plant former workers, who have been exposed to metallic mercury vapors for a long time, and including numerous cases of chronic mercury intoxication (CMI).
  
  
  METHODS
  Polymorphisms in HSP70 gene family members (HSP1A1 (+190G/C, rs1043618), HSPA1B (+1267A/G and +2074G/C, rs1061581) and HSP1AL (+2437T/C, rs2227956)) genes were studied among 120 male workers involved in caustic soda production by mercury electrolysis at 2 plants in Eastern Siberia. These subjects had been chronically exposed to metallic mercury vapors for > 5 years and divided into 3 groups based on the occurrence and time of the CMI diagnosis, or absence of this disease. The Group 1 consisted of individuals (N = 46), who had had contact with mercury but were not diagnosed with the CMI. The Group 2 included workers (N = 56), who were diagnosed with the CMI longer than 14 years ago. The Group 3 consisted of the subjects (N = 18), who had been diagnosed with the CMI 3-5 years ago. The logistic regression analysis was used for 3 genetic models with and without adjustment for age and duration of mercury vapor exposure.
  
  
  RESULTS
  We found that genotypes СС-HSPA1A (+190G/C) and GG-HSPA1B (+1267A/G) had a high predictive risk of the CMI development (adjusted odds ratio (ORadj) = 5.58, p = 0.026 and ORadj= 14.7, p = 0.0015, respectively). Twelve individuals with the CMI had a specific combination of СС-HSPA1A (+190G/C) and GG-HSPA1B (+1267A/G) genotypes, which strongly associated with the diagnosis (ORadj= 12.3, p = 0.0285). Moreover, significant association with the CMI was also obtained for the haplotype G-C of 1267A/G and 190G/C polymorphisms (OR = 2.1, p = 0.018).
  
  
  CONCLUSIONS
  The association of СС-HSPA1A (+190G/C) and GG-HSPA1B (+1267A/G) genotypes and their combination for the CMI individuals suggests the role for HSPA1 genes in mercury-dependent mechanisms of the CMI development and progression. Int J Occup Med Environ Health 2017;30(1):77-85.
authors.affiliation: East-Siberian Institute of Medical and Ecological Research, Angarsk, Russia (Biochemical Group). yuri_chernyak@hotmail.com.
authors.forename: Yury I
authors.initials: YI
authors.lastname: Chernyak
authors.affiliation: East-Siberian Institute of Medical and Ecological Research, Angarsk, Russia (Biochemical Group). alek-merinov@mail.ru.
authors.forename: Alla P
authors.initials: AP
authors.lastname: Merinova
mesh_terms: D000328:Adult; D020022:Genetic Predisposition to Disease; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics*; D006801:Humans; D008297:Male; D008630:Mercury Poisoning / Q000235:genetics*; D008875:Middle Aged; D009784:Occupational Diseases / Q000235:genetics*; D016017:Odds Ratio; D011110:Polymorphism, Genetic; D012307:Risk Factors; D012800:Siberia
chemical_list: D018840:HSP70 Heat-Shock Proteins
keywords: HSPA1 polymorphisms; association with chronic mercury intoxication; chronic mercury intoxication; chronic mercury vapor exposure; genetics in occupational health; heat shock protein 70