Introduction: A particular single nucleotide polymorphism (rs174547) was identified in the FADS1 gene according to published data, with significant association between its variants and the metabolism of fatty acids. Objective: To develop, adapt and verify methodology for detection and analysis of FADS1 genetic variants (SNPs) in a small scale setting (pilot study), as these SNPs have been associated with the metabolism of fatty acids. Methods: A specific primer set targeted at the SNP region was designed and the reaction was optimized under various conditions: primer concentrations, reaction temperatures, duration and number of amplification cycles, etc. A pilot group of 10 subjects from Bulgarian volunteers were randomly picked and tested in order that the optimized conditions were verified. Following standard DNA extraction from buccal swabs, a polymerase chain reaction was performed amplifying a 243 bp fragment, with the C/T SNP contained inside. The amplicon was visualized after 40 min electrophoresis on a 2% agar's gel. Products were then run on a capillary sequencer (Sanger type sequencing), and obtained data were read with the MEGA5 software. Results: The proposed system for detection and analysis of SNPs in the FADS1 gene was optimized and probated for the first time in Bulgaria. Thus, although a small-scale pilot study, its results represent primary data originated from Bulgarian individuals. It was shown that under the optimized reaction condition our primer systems produced an amplicon with the expected size and indeed contained a fragment from the FADS1 gene, with the analyzed C/T SNP inside. Conclusions: The introduction of molecular biomarkers would allow an individual assessment of the fatty acid metabolism to be made.Thereby, the developed and probated methodology, if is to be applied in a large scale setting, would help to investigate the relationship and influence of genetic predisposition, individual metabolism and food intake.

High sodium intake is associated with increased blood pressure and and increased risk of cardiovascular disease (CVD). Among the countries of the European Union, Bulgaria ranks first in mortality from CVD. Genetically determined salt sensitivity is present in 50% of the hypertensive and 26% of the normotensive population, posing a major public health problem. The present study was conducted within the National Program for Prevention of Chronic Non-Communicable Diseases 2014 - 2020 to assess the sodium intake of the population in Bulgaria. 36 normotensive participants are included in the study. DNA from each volunteers was isolated and genotyped for rs10177833 (A>C) in SLC4A5 gene by TaqMan SNP genotyping assay. To determine the 24-hour urinary excretion of sodium in the subjects, a random sample was taken from each participant. Sodium concentration was determined by atomic absorption spectrometry. A WHO protocol has been used to recalculate sodium excretion (Protocol for Sodium Determination in 24-hour Urine Samples). Eighteen of total of 35 participants had wild AA genotype (51.43%), thirteen were heterozygotes (37.14%) and four were carriers of two polymorphic C alleles (11.43%). The frequency of A allele of rs10177833 (A>C) in SLC4A5 gene was 70%, whereas polymorphic C allele was only 30%. The correlation analysis showed negative statistical significant relationship between rs10177833 in SLC4A5 gene and sodium concentration (in milligrams) in 24 - hours urine (r = -0.365, p = 0.031). Also the holders of CC genotype had significant lower values of Na compared to these with wild AA genotype (p = 0.01) and compared to heterozygotes (p = 0.019). In conclusion, we found a clear relationship between the polymorphic variant rs10177833 in SLC4A5 gene and the concentration of sodium in urine in Bulgarian normotensives. The tendency of association was found between the studied polymorphic variant and blood pressure values, which should be studied in a large number of participants Key messages Increasing the population's awareness of health risks with increased salt consumption. Regular monitoring of salt consumption.

The input of molecular genetic biomarkers allows individual assessment of metabolic pathways and the behaviour of the major enzymes responsible for nutrient conversion. This in turn enriches the nutrigenetic information fund, and the panels of well-studied gene variants and their interaction with nutrients can be used to create precise personalized diets. Our objective was to determine the significance of the rs174547 genetic variant in the fatty acid desaturase 1 (FADS1) gene in the metabolism of saturated and unsaturated fatty acids ingested with food and to identify the potential of FADS1 rs174547 as a molecular genetic marker to be included in a panel of nutrigenetic studies in order to prepare a personalized diet plan. A total of 123 volunteers (43 men and 80 women) from Bulgaria, aged 28 to 65 years, were tested for rs174547 in the FADS1 gene. A DNA sample was taken from each volunteer by a non-invasive method (buccal swabs), and the genetic variant of each individual was determined by molecular genetic approaches. Their general health was assessed by taking anthropometric and body impedance measurements data and completing a lifestyle survey. The lipid profile included testing for triglycerides, total cholesterol, HDL and LDL cholesterol, and blood sugar. Information on the total food intake was collected through questionnaire methods. The results of the statistical tests show that there is a statistically significant difference between the two genotypes only in HDL cholesterol levels (P = 0.044, at P < 0.05) - carriers of the C/T genotype have lower mean concentration values of HDL-cholesterol (1.27 mmol/l) than for T/T variant carriers (1.48 mmol/l). Among men, there were statistically significant differences in mean levels of total cholesterol (P = 0.012) and HDL cholesterol (P = 0.008) between the two genotypes. Among women, there was a statistically significant difference between the two genotypes only in terms of mean triglyceride levels (P = 0.007). The differences in the other studied indicators do not satisfy the criterion for significance (P < 0.05). The results suggest an effect of the intake of SFA (saturated fatty acids) and MUFA (monounsaturated fatty acids) on the relationship between rs174547 polymorphism and plasma lipids (total and LDL-cholesterol) only in men. Studies of the Bulgarian population prove extremely low intake of omega-3 fatty acids due to low consumption of fish. These findings and the lack of data for Bulgaria on genetic variants of FADS1 are a prerequisite for conducting in-depth studies of both risk groups, such as patients with cardiovascular disease, dyslipidaemia or nutritional deficiency of LC-PUFAs, and in healthy people.