Frequency of adult type-associated lactase persistence LCT-13910C/T genotypes in the Czech/Slav and Czech Roma/Gypsy populations

Pilot study of correlation of selected genetic factors with cribra orbitalia in individuals from a medieval population from Slovakia

OBJECTIVE

The aim of this study is to investigate the potential genetic etiology of cribra orbitalia noted on human skeletal remains.

MATERIALS

We obtained and analyzed ancient DNA of 43 individuals with cribra orbitalia. The analyzed set represented medieval individuals from two cemeteries in western Slovakia, Castle Devín (11th-12th century AD) and Cífer-Pác (8th-9th century AD).

METHODS

We performed a sequence analysis of 5 variants in 3 genes associated with anemia (HBB, G6PD, PKLR), which are the most common pathogenic variants in present day of European populations, and one variant MCM6:c.1917 + 326 C>T (rs4988235) associated with lactose intolerance.

RESULTS

DNA variants associated with anemia were not found in the samples. The allele frequency of MCM6:c.1917 + 326 C was 0.875. This frequency is higher but not statistically significant in individuals displaying cribra orbitalia compared to individuals without the lesion.

SIGNIFICANCE

This study seeks to expand our knowledge of the etiology of cribra orbitalia by exploring the potential association between the lesion and the presence of alleles linked to hereditary anemias and lactose intolerance.

LIMITATIONS

A relatively small set of individuals were analyzed, so an unequivocal conclusion cannot be drawn. Hence, although it is unlikely, a genetic form of anemia caused by rare variants cannot be ruled out.

SUGGESTIONS FOR FURTHER RESEARCH

Genetic research based on larger sample sizes and in more diverse geographical regions.

Anthropometric and metabolic profile of children with gene polymorphisms for primary lactose intolerance

Primary lactose intolerance is caused by a genetically programmed loss in lactase production after 5-6 years of age. Milk and dairy products are often incriminated as a cause of gastrointestinal symptoms. Recent studies show that lactase persistence in adult life correlates with higher anthropometric indexes and an altered metabolic profile. We aimed to assess whether the presence of gene polymorphisms for primary lactose intolerance has an influence on the anthropometric and metabolic profile of children. We conducted a cross-sectional study, recruiting consecutive children evaluated at the 2nd Pediatric Clinic, Timisoara from May to August 2016. We enrolled 87 children aged 6-17 years [mean age 10.64±3.51 years; 45 (51.72%) girls]. Subjects were asked to complete an analogue visual scale of symptoms. We measured weight, height, blood pressure and calculated body mass index. The metabolic profile included fasting blood glucose, triglycerides and HDL cholesterol levels. We used strip genotyping to identify gene polymorphisms for primary lactose intolerance. According to the results, our study population was grouped into lactose tolerant (n=42) and lactose intolerant (n=45) groups. No differences were found in regards to weight, height, body mass index and blood pressure between the two study groups. Glucose, triglycerides and HDL cholesterol were similar in the lactose intolerant and lactose tolerant children. The presence of gene polymorphisms for primary lactose intolerance did not influence the children's anthropometric and metabolic profile.

Increased prevalence of the CVD-associated ANRIL allele in the Roma/Gypsy population in comparison with the majority Czech population

Cardiovascular disease (CVD) is a major cause of death around the world, with highest prevalence reported in minority Roma/Gypsy populations living in developed countries. Whether these differences are caused by unhealthy lifestyles or genetic factors remain unknown. The aim of our study was to examine the genotype frequencies of the rs10757274 polymorphism in the 9p.21 locus within ANRIL (antisense non-coding RNA in the INK4 locus), a long non-coding RNA located in the vicinity of the CDKN2A/2B inhibitors loci. ANRIL is understood to be the strongest genetic determinant of CVD in Caucasians. Using PCR-RFLP, we analysed the ANRIL rs10757274 polymorphism in 298 non-Roma (50% male) and 302 Roma/Gypsy (50% male) adult (39.5 ± 15.1 years and 39.2 ± 12.8 years, respectively) subjects. We found that frequencies of the ANRIL GG, GA and AA genotypes were 20.1%, 52.4% and 27.5% in the majority population and 32.9%, 47.9% and 19.2% in Roma/Gypsy subjects, respectively. The distribution of genotypes was deemed significantly different at P < 0.001. Within the Roma/Gypsy population, we detected increased prevalence of the CVD-associated GG genotype. Increased prevalence of CVD among Roma/Gypsies subjects may be significantly linked to genetic background.

Genetics of Lactose Intolerance: An Updated Review and Online Interactive World Maps of Phenotype and Genotype Frequencies

In humans the ability to digest milk lactose is conferred by a β-galactosidase enzyme called lactase-phlorizin hydrolase (LPH). While in some humans (approximately two-thirds of humankind) the levels of this enzyme decline drastically after the weaning phase (a trait known as lactase non-persistence (LNP)), some other individuals are capable of maintaining high levels of LPH lifelong (lactase persistence (LP)), thus being able to digest milk during adulthood. Both lactase phenotypes in humans present a complex genetic basis and have been widely investigated during the last decades. The distribution of lactase phenotypes and their associated single nucleotide polymorphisms (SNPs) across human populations has also been extensively studied, though not recently reviewed. All available information has always been presented in the form of static world maps or large dimension tables, so that it would benefit from the newly available visualization tools, such as interactive world maps. Taking all this into consideration, the aims of the present review were: (1) to gather and summarize all available information on LNP and LP genetic mechanisms and evolutionary adaptation theories, and (2) to create online interactive world maps, including all LP phenotype and genotype frequency data reported to date. As a result, we have created two online interactive resources, which constitute an upgrade over previously published static world maps, and allow users a personalized data exploration, while at the same time accessing complete reports by population or ethnicity.

Different prevalence of T2DM risk alleles in Roma population in comparison with the majority Czech population

BACKGROUND

The Czech governmental study suggests up to a 25% higher prevalence of type 2 diabetes mellitus (T2DM) in the Roma population than within the majority population. It is not known whether and to what extent these differences have a genetic background.

METHODS

To analyze whether the frequencies of the alleles/genotypes of the FTO, TCF7L2, CDKN2A/2B, MAEA, TLE4, IGF2BP2, ARAP1, and KCNJ11 genes differ between the two major ethnic groups in the Czech Republic, we examined them in DNA samples from 302 Roma individuals and 298 Czech individuals.

RESULTS

Compared to the majority population, Roma are more likely to carry risk alleles in the FTO (26% vs. 16% GG homozygotes, p < .01), IGF2BP2 (22% vs. 10% TT homozygotes, p < .0001), ARAP1 (98% vs. 95% of A allele carriers, p < .005), and CDKN2A/2B (81% vs. 66% of TT homozygotes, p < .001) genes; however, less frequently they are carriers of the TCF7L2 risk allele (34% vs. 48% of the T allele p < .0005). Finally, we found significant accumulation of T2DM-associated alleles between the Roma population in comparison with the majority population (25.4% vs. 15.2% of the carriers of at least 12 risk alleles; p < .0001).

CONCLUSION

The increased prevalence of T2DM in the Roma population may have a background in different frequencies of the risk alleles of genes associated with T2DM development.

Five genetic polymorphisms of cytochrome P450 enzymes in the Czech non-Roma and Czech Roma population samples

Objectives Cytochromes P450 play a role in human drugs metabolic pathways and their genes are among the most variable in humans. The aim of this study was to analyze genotype frequencies of five common polymorphisms of cytochromes P450 in Roma/Gypsy and Czech (non-Roma) population samples with Czech origin. Methods Roma/Gypsy (n=302) and Czech subjects (n=298) were genotyped for CYP1A2 (rs762551), CYP2A6 (rs4105144), CYP2B6 (rs3745274) and CYP2D6 (rs3892097; rs1065852) polymorphisms using PCR-RFLP or Taqman assay. Results We found significant allelic/genotype differences between ethnics in three genes. For rs3745274 polymorphism, there was increased frequency of T allele carriers in Roma in comparison with Czech population (53.1 vs. 43.7%; p=0.02). For rs4105144 (CYP2A6) there was higher frequency of T allele carriers in Roma in comparison with Czech population (68.7 vs. 49.8%; p<0.0001). For rs3892097 (CYP2D6) there was more carriers of the A allele between Roma in comparison with Czech population (39.2 vs. 38.2%; p=0.048). Genotype/allelic frequencies of CYP2D6 (rs1065852) and CYP1A2 (rs762551) variants did not significantly differ between the ethnics. Conclusions There were significant differences in allelic/genotype frequencies of some, but not all cytochromes P450 polymorphisms between the Czech Roma/Gypsies and Czech non-Roma subjects.

Five genetic polymorphisms of cytochrome P450 enzymes in the Czech non-Roma and Czech Roma population samples

Objectives Cytochromes P450 play a role in human drugs metabolic pathways and their genes are among the most variable in humans. The aim of this study was to analyze genotype frequencies of five common polymorphisms of cytochromes P450 in Roma/Gypsy and Czech (non-Roma) population samples with Czech origin. Methods Roma/Gypsy (n=302) and Czech subjects (n=298) were genotyped for CYP1A2 (rs762551), CYP2A6 (rs4105144), CYP2B6 (rs3745274) and CYP2D6 (rs3892097; rs1065852) polymorphisms using PCR-RFLP or Taqman assay. Results We found significant allelic/genotype differences between ethnics in three genes. For rs3745274 polymorphism, there was increased frequency of T allele carriers in Roma in comparison with Czech population (53.1 vs. 43.7%; p=0.02). For rs4105144 (CYP2A6) there was higher frequency of T allele carriers in Roma in comparison with Czech population (68.7 vs. 49.8%; p<0.0001). For rs3892097 (CYP2D6) there was more carriers of the A allele between Roma in comparison with Czech population (39.2 vs. 38.2%; p=0.048). Genotype/allelic frequencies of CYP2D6 (rs1065852) and CYP1A2 (rs762551) variants did not significantly differ between the ethnics. Conclusions There were significant differences in allelic/genotype frequencies of some, but not all cytochromes P450 polymorphisms between the Czech Roma/Gypsies and Czech non-Roma subjects.

Distribution of ADH1B genotypes predisposed to enhanced alcohol consumption in the Czech Roma/Gypsy population

OBJECTIVE

The aim of the study was to analyse the frequencies of rs1229984 genotypes within the alcohol dehydrogenase (ADH1B) gene in a Gypsies/Roma population and compare them with other populations and with ethanol consumption.

METHODS

We analysed the ADH1B (rs1229984; Arg47→His; c.143G>A) genotype using the Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) in two ethnically different groups - Gypsies/Roma (N = 301) and Czechs (N = 300) where one day alcohol consumption was recorded.

RESULTS

ADH1B genotype/allelic frequencies did not significantly differ between the populations (p = 0.32). The frequency of minor A allele carriers was slightly higher in Gypsies/Roma (14.7%) than in Czechs (11.9%). The prevalence of subjects reporting alcohol intake on the previous day was non-significantly lower in Gypsies/Roma (10.5% vs. 16.4%), as was the amount of alcohol consumed the day before the examination in ethanol consumers (36.1 ± 18.3 g vs. 43.0 ± 27.2 g).

CONCLUSIONS

The frequency of rs1229984 genotypes in the ADH1B gene within the Gypsies/Roma population corresponds with frequencies obtained in North India/Central Asia, the putative country of this ethnic origin. Our results suggest that the minority Gypsies/Roma population consume slightly less alcohol than the Czech majority population.

Intestinal Microbiota in Hirschsprung Disease

OBJECTIVES

The aim of the study was to characterize the microbiota profiles of patients with Hirschsprung disease (HD) and to evaluate this in relation to postoperative bowel function and the incidence of Hirschsprung-associated enterocolitis (HAEC).

METHODS

All patients operated on for HD at our center between 1987 and 2011 were invited to answer questionnaires on bowel function and to participate in a clinical follow-up for laboratory investigations, including fecal DNA extraction, fecal calprotectin (FC), and brush border lactase (LCT) genotyping. The microbiota compositions of patients with HD were compared with those of healthy controls aged between 2 and 7 years.

RESULTS

The microbiota composition of eligible patients with HD (n = 34; median age 12 [range, 3-25] years) differed from the healthy controls (n = 141), showing decreased overall microbial richness (P < 0.005). Seventy-seven percent had experienced HAEC. Normal maturation of the intestinal flora was not observed, but patients had a significantly increased abundance of Proteobacteria among other taxa (P < 0.005) resulting in a reduced carbohydrate degradation potential, as predicted by the taxonomic composition. Genetic lactase deficiency was present in 17% and did not correlate with bowel symptoms. No patients reported active HAEC at the time of sampling and FC was within the normal range in all samples.

CONCLUSIONS

Patients with HD and HAEC had a significantly altered intestinal microbiome compared to healthy individuals, characterized by a lack of richness and pathologic expansions of taxa, particularly Enterobacteria and Bacilli. Further evaluation is needed to identify whether these observations are intrinsic to HD or secondary to the recurrent use of antibiotics during early childhood.