Frequency of the hemochromatosis gene mutations in the population of Serbia and Montenegro

The evolutionary adaptation of the C282Y mutation to culture and climate during the European Neolithic

Objectives

The C282Y allele is the major cause of hemochromatosis as a result of excessive iron absorption. The mutation arose in continental Europe no earlier than 6,000 years ago, coinciding with the arrival of the Neolithic agricultural revolution. Here we hypothesize that this new Neolithic diet, which originated in the sunny warm and dry climates of the Middle East, was carried by migrating farmers into the chilly and damp environments of Europe where iron is a critical micronutrient for effective thermoregulation. We argue that the C282Y allele was an adaptation to this novel environment.

Materials and Methods

To address our hypothesis, we compiled C282Y allele frequencies, known Neolithic sites in Europe and climatic data on temperature and rainfall for statistical analysis.

Results

Our findings indicate that the geographic cline for C282Y frequency in Europe increases as average temperatures decrease below 16°C, a critical threshold for thermoregulation, with rainy days intensifying the trend.

Discussion

The results indicate that the deleterious C282Y allele, responsible for most cases of hemochromatosis, may have evolved as a selective advantage to culture and climate during the European Neolithic. Am J Phys Anthropol 160:86–101, 2016. © 2016 The Authors American Journal of Physical Anthropology Published by Wiley Periodicals, Inc.

Unique frequencies of HFE gene variants in Roma/Gypsies

The aim of this study was to assess the frequencies of three hemochromatosis gene (HFE) mutations in ethnic Roma/Gypsies in Slovakia. A cohort of 367 individuals representing general population and not preselected for health status was genotyped by TaqMan real-time PCR assay for C282Y, H63D and S65C mutations in HFE gene. A unique genetic profile was revealed: C282Y is found in the highest frequency of all Central European countries (4.90%), while the frequency of H63D mutation (4.09%) is lower than any reported in Europe so far. S65C mutation was not present in the cohort. These mutation frequencies can be explained rather by gene influx and genetic isolation than by genetic inheritance from a former Roma/Gypsy homeland.

Prevalence of 845G>A HFE mutation in Slavic populations: an east-west linear gradient in South Slavs

AIM

To compare A allele frequencies of the 845G>A mutation of 10 Slavic populations in central, eastern, and southern Europe between each other and with other European populations.

METHODS

The 845G>A mutation from the DNA of 400 Polish neonates collected in 2005-2006 was analyzed by polymerase chain reaction-restriction fragment length polymorphism. The data were compared with reports from other countries.

RESULTS

We identified 381 GG homozygotes, 18 GA heterozygotes, and 1 AA homozygote. The 845A allele frequency was 2.5%, which makes the summary figure for Poland from this and previous studies 3.5%. The average prevalence for Poland and other West Slavic countries was 3.6%, similar to Russia (inhabited by the East Slavs, 3.5%). The average prevalence in South Slavic countries was 2.2%, gradually decreasing from 3.6% in Slovenia to 0% in Bulgaria, with a longitudinal linear gradient (adjusted R(2)=0.976, P<0.001).

CONCLUSIONS

The West and East Slavs, together with Finland, Estonia, Germany, Austria, Hungary, Slovenia, and Croatia, form a group with 845A allele frequencies between 3% and 4%. In the South Slavs, there is a gradual decline in the prevalence of 845A allele from northwest to southeast, with a surprisingly exact east-west linear gradient.

Hemochromatosis gene mutations in the general population of Slovakia

This is an epidemiologic study of the Slovak population with the aim of determining the frequencies of three hemochromatosis gene (HFE) variants C282Y, H63D and S65C known to be associated with manifestation of hereditary hemochromatosis and to assess deviations of these frequencies from those reported elsewhere. Mutations were detected in 359 ethnic Slovaks by real-time PCR assay based on TaqMan technology. The allelic frequencies were 4.03% for C282Y, 12.67% for H63D and 1.25% for S65C mutation. We observed 0.28% of C282Y/C282Y homozygotes, 3.34% H63D/H63D homozygotes, 0.84% of C282Y/H63D compound heterozygotes and 0.56% of H63D/S65C compound heterozygotes. This is the first time the frequencies of H63D and S65C mutations have been reported in the general population in Slovakia. The observed allelic frequencies are consistent with the previous studies of Slavic and Central European populations.

Mutant HFE genotype leads to significant iron overload in patients with liver diseases from western Romania

The present study aimed at assessing the frequency of HFE mutations (C282Y, H63D and S65C) in western Romanian patients with liver disease of diverse aetiologies suspected of iron overload. A total of 21 patients, all Romanian residents hospitalized with clinical suspicion of iron overload and liver disease, were assayed for C282Y, H63D and S65C mutations, serum ferritin and viral hepatitis markers. Overall, 9 out of the 21 patients (42.86%) were found to harbour mutations in the HFE gene: 4 homozygotes C282Y (19.0%), 1 compound heterozygote C282Y/H63D (4.8%), 1 single heterozygote C282Y (4.8%), 2 single heterozygotes H63D (9.5%), 1 single heterozygote S65C (4.8%), and 12 wild-type cases (57.1%). Among the subgroup of 10 patients with the most prominent signs of iron overload (hyperferritinaemia and/or hepatocyte iron score > or = 1), without hepatocellular carcinoma, the HFE genotypes were conclusive in 5 cases (50%). They had significantly increased ferritin levels compared to wild-type cases (P = 0.029). The inclusion of iron studies during routine clinical visits, coupled with the availability of HFE genotyping for family and population studies, should facilitate the early detection of hereditary haemochromatosis in Romania.

Prevalence of H63D, S65C and C282Y hereditary hemochromatosis gene mutations in Slovenian population by an improved high-throughput genotyping assay

BACKGROUND

Hereditary hemochromatosis (HH) is a common genetic disease characterized by excessive iron overload that leads to multi-organ failure. Although the most prevalent genotype in HH is homozygosity for C282Y mutation of the HFE gene, two additional mutations, H63D and S65C, appear to be associated with a milder form of HH. The aim of this study was to develop a high-throughput assay for HFE mutations screening based on TaqMan technology and to determine the frequencies of HFE mutations in the Slovenian population.

METHODS

Altogether, 1282 randomly selected blood donors from different Slovenian regions and 21 HH patients were analyzed for the presence of HFE mutations by an in-house developed real-time PCR assay based on TaqMan technology using shorter non-interfering fluorescent single nucleotide polymorphism (SNP)-specific MGB probes. The assay was validated by RFLP analysis and DNA sequencing.

RESULTS

The genotyping assay of the H63D, S65C and C282Y mutations in the HFE gene, based on TaqMan technology proved to be fast, reliable, with a high-throughput capability and 100% concordant with genotypes obtained by RFLP and DNA sequencing. The observed frequency of C282Y homozygotes in the group of HH patients was only 48%, others were of the heterogeneous HFE genotype. Among 1282 blood donors tested, the observed H63D, S65C and C282Y allele frequency were 12.8% (95% confidence interval (CI) 11.5-14.2%), 1.8% (95% CI 1.4-2.5%) and 3.6% (95% CI 3.0-4.5%), respectively. Approximately 33% of the tested subjects had at least one of the three HH mutations, and 1% of them were C282Y homozygotes or compound heterozygotes C282Y/H63D or C282Y/S65C, presenting an increased risk for iron overload disease. A significant variation in H63D allele frequency was observed for one of the Slovenian regions.

CONCLUSION

The improved real-time PCR assay for H63D, S65C and C282Y mutations detection is accurate, fast, cost-efficient and ready for routine screening and diagnostic procedures. The genotype frequencies in the Slovenian population agree with those reported for the Central European populations although some deviations where observed in comparison with other populations of Slavic origin. Regional distribution of the mutations should be considered when planning population screening.