Two polymorphisms of presenilin-2 gene (PSEN2) 5' regulatory region are not associated with Alzheimer's disease (AD) in the Polish population

Presenilin 2 gene (PSEN2) is one of the causative genes for familial Alzheimer's disease. A delA polymorphism located in PSEN2 promoter was proposed to be a risk factor for early-onset AD. We examined association between AD and PSEN2 polymorphisms located in two 5'UTR regions in group of 217 late-onset AD patients, 109 mild cognitive impairment patients, and 225 non-demented control subjects. No significant differences for genotype and allele distributions of a delA and a novel insAC polymorphisms in the studied groups as compared to controls were observed. Univariate and multivariate risk estimation shows that neither delA, insAC alleles nor the genotypes are risk factors for AD. No significant interaction between the APOE4 and PSEN2 polymorphisms was found. A bioinformatic analysis showed that delA polymorphism influences binding sites of transcription factors involved in the cellular processes related to AD. The rare variants identified in exon 3 of the PSEN2 could have a potential influence on PSEN2 transcript splicing.

Prion protein gene M129 allele is a risk factor for Alzheimer's disease

Prion protein gene polymorphism M129V represents a known risk factor for Creutzfeldt-Jakob disease. Recently, the meta-analysis revealed that homozygosity at codon 129 is connected with increased risk of Alzheimer's disease (AD). To determine whether M129V polymorphism is a risk factor for AD we analyzed a group of early-onset, and late-onset Polish AD patients. We observed that in LOAD patients there is a statistically significant increase of MM (p=0.0028) and decrease of MV (p=0.0006) genotype frequency, as compared to controls. When both groups were stratified according to APOE4 status, increase of MM and decrease of MV genotype frequency were significant in the LOAD subgroup with no APOE4 (p=0.017, and p=0.018, respectively). In the subgroup with APOE4 allele, only MV genotype frequency was significantly lower, as compared to controls (p=0.035). However, no interaction was found between APOE4 status and M129V polymorphism. We conclude that MM genotype increases LOAD risk in Polish population independently from the APOE4 status.

The -22c/t polymorphism in presenilin 1 gene is not connected with late-onset and early-onset familial Alzheimer's disease in Poland

The -22c/t polymorphism in the promoter of the presenilin 1 gene is associated with increased risk for Alzheimer's disease (AD) in some populations. It was shown that -22c allele is connected with two-fold decrease in promoter activity. We studied the impact of the polymorphism in groups of Polish late-onset and early-onset AD patients. Our results suggest that -22c/t polymorphism is not connected with AD in Polish population. The -22t allele showed a high degree of linkage disequilibrium with -2797 insertion of 13 bp. An additional -2923g/t polymorphism is also not connected with -22c/t and is not a risk factor for AD.

[Occupational risk factors for breast cancer in the epidemiological studies]

The paper reviews data on the occupational risk factors, which role in the etiology of breast cancer in women has been analyzed and estimated in the epidemiological studies. The results of the studies are presented and discussed. An increased incidence or risk of death from breast cancer was observed in some studies among teachers, nurses and physicians, managerial occupations, beauticians and hairdressers, chemists, telephone and telegraph operators, workers of the pharmaceutical and chemical industry. Some epidemiological studies indicate that breast cancer incidence might be related to occupational exposure to electromagnetic fields, ionizing radiation, low physical activity, organic solvents, selected pesticides. However, owing to inconsistency of the study results and methodological weaknesses (imprecise classification of exposure, low response rate, uncontrolled confounding) no definite conclusion can be drawn.

A mortality study of workers with reported chronic occupational carbon disulfide poisoning

A mortality cohort study was carried out on 2,291 workers, including 169 women, with chronic occupational CS2 poisoning diagnosed during the years 1970-90. Information on vital status was available for 98.2% as of December 31, 1992. Mortality assessment was based on the standardized mortality ratio using the person-years method. The general population of Poland was the reference population. The number of subjects who died during the period of observation accounted for 658 men and 21 women. The analysis of mortality in male subjects showed statistically significant excess of deaths from the circulatory system diseases (SMR = 139), in this from ischaemic heart disease (SMR = 137), cerebrovascular disease (SMR = 188) and colon cancer (SMR = 233). Over a two-fold increased risk of death from diseases of the nervous system and sense organs, although statistically insignificant, was also observed. Among women a statistically significant risk of death from atherosclerosis was noted (SMR = 286). An elevated risk of death from the circulatory system diseases and from ischaemic disease (IHD) agrees with the results of some other cohort studies carried out in the viscose rayon workers. The increased mortality from malignant neoplasms is an unusual finding in cohorts of workers exposed to CS2. Our own data reported here showed a significantly increased mortality from colon cancer (9 cases). All these cases were noted in workers of the two oldest rayon plants and they require a detailed analysis. Further survey is also needed to elucidate the excess of deaths from the nervous system and sense organs diseases.