Skip to main content
Download PDF
  • Research article
  • Open access
  • Published:

Frequency of APOE, MTHFR and ACE polymorphisms in the Zambian population

BMC Research Notes volume 7, Article number: 194 (2014) Cite this article

Abstract

Background

Polymorphisms within the apolipoprotein-E (APOE), Methylenetetrahydrofolate reductase (MTHFR) and Angiotensin I-converting enzyme (ACE) genes has been associated with cardiovascular and cerebrovascular disorders, Alzheimer’s disease and other complex diseases in various populations. The aim of the study was to analyze the allelic and genotypic frequencies of APOE, MTHFR C677T and ACE I/D gene polymorphisms in the Zambian population.

Results

The allele frequencies of APOE polymorphism in the Zambian populations were 13.8%, 59.5% and 26.7% for the ε2, ε3 and ε4 alleles respectively. MTHFR C677T and ACE I/D allele frequencies were 8.6% and 13.8% for the T and D minor alleles respectively. The ε2ε2 genotype and TT genotype were absent in the Zambian population. The genetic distances between Zambian and other African and non-African major populations revealed an independent variability of these polymorphisms.

Conclusion

We found that the APOE ε3 allele and the I allele of the ACE were significantly high in our study population while there were low frequencies observed for the MTHFR 677 T and ACE D alleles. Our analysis of the APOE, MTHFR and ACE polymorphisms may provide valuable insight into the understanding of the disease risk in the Zambian population.

Background

The burden of non-communicable diseases such as stroke and cardiovascular disease is increasing in Sub-Saharan Africa (SSA) [1, 2]. Their development is most likely caused by the interaction of multiple genetic factors and known risk factors (hypertension, diabetes, dyslipidemia, and smoking). One of the challenges for translating disease associated polymorphisms into clinical application is the lack of knowledge regarding the frequency of the polymorphism in the targeted population. Without this information, population-attributable risk remains unknown. In addition, factors that could affect the association of the allele with disease, either positively or negatively, such as ethnicity and gender, may not be possible to determine without population based allele frequencies [3].

A number of genetic polymorphisms, such as Apolipoprotein E (APOE). Methylenetetrahydrofolate reductase (MTHFR) and Angiotensin I-converting enzyme (ACE), have been studied in relation to age-related disorders. Specific polymorphisms in these genes have been implicated in various complex disorders including cerebrovascular disease (CVD), coronary artery disease (CAD) and Alzheimer’s disease (AD) [4–7].

For example, ACE is an enzyme of the renin-angiotensin system (RAS) catalyzing the conversion of angiotensin I to angiotensin II which is implicated in fluid and electrolytes balance. Angiotensin II has vasoconstrictor effect hence contributing to systemic blood pressure control, it also inhibits the release of acetylcholine (anticholinergic effect) and has pro-inflammatory effect [8].

The ACE polymorphism is characterized by the presence (insertion or I) or the absence (deletion or D) of Alu Ya5 inside intron 16 giving three possible genotypes (homozygote II, heterozygote ID and homozygote DD). The frequency of the insertion/deletion I/D polymorphism of the ACE gene has been widely investigated since it was identified by Rigat et al. [8]. The authors further observed that the highest serum ACE activity was in the DD genotype as opposed to II genotype in which the lowest activity was found [9]. Many authors have suggested the ACE I/D variants predisposes the individual to CAD, hypertension, stroke and diabetes mellitus [10–17]. Several studies have reported a reduction of the incidence and rate of the cognitive decline in AD after starting treatment with RAS-acting antihypertensive drugs (ACE inhibitors) and angiotensin receptor blockers (ARB) [18].

The APOE gene encodes a protein which is essential for the normal catabolism of triglyceride rich lipoprotein constituents and modulates lipoprotein metabolism. The APOE gene is polymorphic with three common alleles, ε2, ε3 and ε4 resulting in three distinct protein isoforms Ε2, Ε3 and Ε4 determined by the two amino acid substitutions (R112C and C158R). Several investigations have suggested that the APOΕ4 is the ancestral allele [19, 20] even though it is the risk allele in many diseases such CAD [4], CVD [21] and AD [22]. MTHFR is a folate related enzyme important for remethylation of homocysteine to methionine. Elevated total plasma homocysteine (t-Hcy) concentration was found to be correlated with MTHFR C677T polymorphism. A common polymorphism of the MTHFR gene, C677T, has been reported to be associated with reduced enzyme activity and increased t-Hcy levels [23] and hence, an independent risk factor for stroke, CAD, and AD [24]. The allelic frequencies of these specific polymorphisms in the APOE, MTHFR and ACE genes substantially varies in different regions of the world and among ethnic groups [3, 19, 25, 26] and have not yet been studied in the Zambian population, hence, association of them with stroke, CAD, AD, and other common non-communicable diseases in this population is unclear.

Zambia, officially the Republic of Zambia, is a landlocked country in the central part of southern Africa. Zambia covers an area of 752,614 square kilometers (290,586 square miles) and has a population of almost 13 million, giving the country one of the lowest populations-to-land ratios in Africa. It borders the Democratic Republic of the Congo to the north, Tanzania on the northeast, Malawi on the east, Mozambique, Zimbabwe, Botswana, and Namibia to the south, and Angola on the west [27]. The original inhabitants of all of modern day Zambia, except Western Province, are called Batwa (Khoisan). They were hunters and gatherers who lived a nomadic life. The Khoisans were the only inhabitants of most of Zambia until the 4th century, when they were displaced by the Bantu who started to migrate from the north.Between the 15th century (or possibly earlier) and the 18th century, various groups of Bantu migrants from the southern Congo settled in Zambia [28]. Zambia was influenced by two “invasions” in the mid-19th century. Shaka’s Zulu empire in South Africa set in motion a series of migrations, commonly referred to as the mfecane; groups of peoples, including the Ngoni. The other invasion came in the form of traders from the north. The territory of the present Zambia, being far inland, did not have direct contact with non-Africans until relatively recently in its history. The traders from the north (Nyamwezi, Arabs, and Swahili) drew Zambia into long-distance trading systems [28]. At present Zambia has a mixture of 72 ethnic tribes. However, there are seven (Chewa, Bemba, Lunda, Lozi, Kaonde, Luvale, and Tonga) major ethnic groups who belong to the Bantu people. The Tonga people were one of the first cultures to settle in Zambia. Industrialization and urbanization has seen these ethnically different people brought together by economic interests.

In this study we have evaluated the prevalence of APOE, MTHFR, and ACE gene polymorphisms in the Zambian population and compared those frequencies with African and other populations to provide baseline epidemiological data for future clinical investigations of CVD, CAD, AD, and other diseases in Zambia.

Methods

Sample collection

Blood samples were obtained from one hundred and sixteen (68 women, 48 men) unrelated subjects. The study included subjects between 25 and 60 years (mean age 44 ± 16 years), who indicated their ancestry and belonged to one of 72 ethnic Zambian tribes. All individuals were recruited as part of Zambian Stroke Study [29, 30]. Available clinical records were analyzed for exclusion of major neurological diseases. Subjects known to have risk factors for stroke (hypertension, severe coronary artery disease, diabetes mellitus and hyperlipidemia) were excluded from the study. Pregnant women and HIV positive subjects were also excluded from the study. All participants gave written informed consent and the study was approved by the Biomedical Research Ethics Committee of the University of Zambia.

Genetic analysis

Whole blood was collected in 4 ml EDTA tubes and stored at 4 degrees Celsius prior to DNA extraction. The DNA extraction was performed using silica-gel-based membrane with vacuum technology (QIAamp DNA Mini Kit (250) (QIAgen, London, UK).

Genotyping was performed using fluorescent-labeled PCR technology with ABI TaqMan probes and chemistry (Applied Biosystems, Foster City, CA), amplification was performed with an ABI7900 Real-Time PCR system and analysis performed using SDS 2.2.2 software. Positive and negative controls where included on all TaqMan assay plates. Positive or ambiguous results in the TaqMan assay were also confirmed / resolved with direct sequencing.

Statistical analysis

We determined genetic distance using Carvalli-Sforza and Edwards (1967) method [31] in order to give an overview of the relationship between the Zambian and other populations. The chi-square test was used to test whether observed allele frequencies agreed with those expected in the Hardy-Weinberg equilibrium (HWE). Differences with other populations were assessed using chi-square contingency test.

Results

Genotype and allele frequencies for the Zambian population were as shown in Table 1. Genotyping call-rate was greater than 98% with less than 2% of samples requiring sequencing to resolve or confirm the genotype data. The distribution of MTHFR and APOE genotypes conformed to Hardy-Weinberg equilibrium (HWE) with p = 0.540 and p = 0.456 respectively, while the ACE allele distribution was not according to HWE (p = 0.005) due to an increase in rare minor allele homozygotes. There was no statistically significant difference between male and female data for APOE, MTHFR and ACE polymorphisms (Table 2). Our analysis of the APOE gene showed that the rare E2E2 genotype was absent in our sample. In addition, there was no significant difference between the frequency of the ε3ε3 and ε3ε4 genotypes (p > 0.999) which were the most frequent genotypes observed. The Ε3 allele of APOE polymorphism was found to be the most frequent (0.595), while Ε2 allele had a frequency of 0.138, and Ε4 0.267.

Table 1 Allele and genotype frequencies of the APOE , MTHFR and ACE polymorphisms and HWE in the Zambian population (n = 116)
Full size table
Table 2 Gender frequencies of the APOE , MTHFR and ACE polymorphisms in the Zambian population
Full size table

The distribution of the APOE allele frequencies in the Zambian population has an intermediate position among other African populations. As shown in Table 3 and Figure 1, pooled APOE allele frequencies of the Zambian population was close to Tswanas [32], Ugandans [33], Ghanaians [32], and Tanzanians [34].

Table 3 The APOE allele frequencies in the African populations
Full size table
Figure 1
figure 1

Genetic relationships between populations represented by Multidimensional Scaling Analysis for APOE and MTHFR.

Full size image

The C allele of the MTHFR C677T polymorphism was higher than T allele (p < 0.0001) with frequency of 0.914 and 0.086 respectively. The TT genotype was absent in the Zambian population.

Multidimensional Scaling (MDS) analysis of the MTHFR C677T polymorphism in the African populations, including the Zambian population (Figure 1, Table 4) showed a close relationship with previous studies on the Bantu populations [40].

Table 4 The MTHFR C677T polymorphism allele frequencies in the African populations
Full size table

The current study found that, based on MTHFR C677T polymorphism, Zambian population was closer to coastal Togo and Moroccans were found to be furthest from Zambians (Figure 1). Our data is consistent with published data which shows that the frequency of homozygous mutated genotype TT was absent in most of the investigated African populations [45] According to Murry et al. [46], this data suggests the lethal nature of this genotype in most SSA populations.

The genotypic data for ACE shows that the II genotype was higher than the ID genotype (p < 0.0001) and the DD genotype (p < 0.0001) in the Zambian population. The ACE polymorphism displayed I and D allele frequencies at 0.862 and 0.138 respectively.

The data shows that APO ε3, MTHFR 677C and ACE I alleles were most widespread in the Zambian population. Extensive interethnic variations in the frequency of I and D alleles have been reported worldwide for various populations (Table 5).

Table 5 Allele frequencies of the ACE gene in different ethnic groups
Full size table

Discussion

In this study we have analyzed for the first time polymorphisms of the APOE, MTHFR and ACE genes in the Zambian population. This constitutes an approach to study genetic factors considered as risk factors for CVD, CAD, and AD in this population.

In our study population the APOE allele frequencies of ε2 (0.138), ε3 (0.595), and ε4 (0.267) were within the reported range of African populations [19] and the ε3 was the most prevalent. These allele frequencies varied significantly between Zambian and the North African populations such as Moroccans [36] and Tunisians [37]. The variation may be explained by extensive intermixing of the North African populations with Arab, Jewish and other Western Eurasian populations.

The APOEϵ2 allele frequency range between the Zambian and other African populations was from 7% (Tswana, Botswana) to 11.1% in Haoussa’s of Niger. This variation may be explained according to the ethnolinguistic classification of the African population which identifies the Haoussas as belonging to the Afro-asiatic macro-family while the Zambian population can be classified within the Niger-Kordofanian, the largest of the four ethnolinguistic African macro-families [61]. The APOE ε3 allele frequency range between the Zambian population and other African populations was from 4% (Malagasy [35]) to 34.4% (in Senegalese [35]). The variation of APOE ε4 allele frequency between the Zambian and other African populations was as low as 1.8% between Zambian and Tswana [32] populations and as high as 23.7% between the Zambian and Senegalese populations.

Patterns of genetic variation in modern African populations are shaped by demographic forces such as the Bantu migration [62]. Bantu speakers from West Africa practicing agricultural subsistence farming migrated throughout SSA and subsequently admixed with indigenous populations [61]. According to Gerdes et al. [63], populations with long-established agricultural economy such as the West African, [43, 64] have higher ε3 allele frequency compared to other populations. Higher frequencies of APOE ε3 allele were found in populations around the Middle East probably because they have a longer established agricultural economy compared to West Africa, with the exception of Senegal [19].

The frequency of APOE polymorphisms is highly heterogeneous among African [2, 47, 63] and other populations [26] (Figures 1,2). This heterogeneity illustrates the geographical and ethnic variations resulting from the evolutionary process. It has been suggested that APOE ε2 and ε3 alleles arose by mutation of the ε4 allele [19]. Past studies have showed that the ε3 allele is more widely distributed probably because of positive selection for this allele in these regions [19, 26].

Figure 2
figure 2

Distribution of the APOE ε 4, MTHFR 677 T and ACE D allele frequencies in the African populations.

Full size image

It was found that the APOE ε4 (ancestral) allele frequency is higher in the Khoisan population than the rest of the Bantu populations [2, 26]. According to this data it was suggested that there is a flow of the ε4 allele from the Khoisan to other Bantu populations [19]. However, it is not clear if the increasing of CAD, CVD and AD in the African populations is associated with the ε4 allele frequency. Since the African populations are characterized by greater levels of genetic diversity [63], the association of CAD, CVD, and AD with the ε4 allele frequency needs to be investigated in each of the major ethnic groups of the Zambian population.

Our study showed that C allele of the MTHFR C677T polymorphism was higher than T allele (p < 0.0001) with the TT genotype completely absent. The frequency of MTHFR C677T polymorphism has not been widely studied in African countries. However, few published studies showed that the 677TT genotype and the 677 T allele are markedly lower (below 10%) in the African populations than other ethnic groups [40–46, 65–68].

For instance whites in Europe had 677TT frequency range of 8% to 18% [40] while this frequency for whites outside Europe ranged from 10 to 14% [67]. Amerindians from Brazil had 677TT frequency range of 21% [40].

The difference in the MTHFR alleles among African and other ethnic groups is not yet known. Studies in last decade have shown positive correlation between concentration of folate and the frequency of the 677 T allele [43, 45], and hypothesized of gene-nutrient interaction between MTHFR and folate status [43]. On the basis of these data it was suggested that adequate folic intake in a given population may increase the frequency of the 677 T allele as described in Europeans [45] and Americas [66]. Low frequency of the 677 T allele in African populations, including Zambian population, is probably influenced by folate deficiency due to malnutrition and infectious impairing intestinal absorption of folate [46, 67].

It has been reported that in P. falciparum malaria, there is a correlation between plasma homocysteine (Hcy) concentrations and malaria severity [42, 68]. Some authors suggested that the 677 T carriers with increased level of Hcy are more vulnerable to malaria in SSA [42]. Chronic malaria parasite infections in Zambia remain a significant risk factor for severe anemia, especially in children. Selection for the 677 T allele has been reported in relation to folate intake [69].

Unlike the APOE polymorphism, ACE I/D polymorphism has not been widely studied among the African populations. In this study, the frequency of the D allele in the Zambian population was significantly lower (p < 0.0001) than other African countries. This may be explained by important gene flow between the North African and other Eurasian populations, as it was suggested regarding APOE allele frequencies.

In our data, the ACE polymorphism frequency of the I allele was significantly prevalent compared to D allele (p < 0.0001). However, other studies have reported a high frequency of the D allele in the African populations [17]. The II genotype was higher than the ID genotype (p < 0.0001) and the DD genotype (p < 0.0001) in the Zambian population. The discrepancies in allele and genotype frequencies between Zambian and other populations need further investigations.

The frequency of the D allele of the ACE I/D polymorphism ranged from 0.03 among Australian aborigines to 1.00 among the Abazians in Europe [70–73]. It was reported that the DD was less frequent in Asians than non-Asians [73, 74].

Previous investigations have suggested a genetic predisposition of ACE I/D polymorphism with CAD [75, 76], CVD [77], diabetes mellitus [78] However, there were significant inter-ethnic variations [17, 70, 71]. There was no statistically significant gender difference in our study group for the investigated polymorphisms.

In interpreting the findings of this study it is essential to consider its limitations. The small sample size cannot be representative of all the Zambian population. However, this will be a stepping stone to larger ongoing clinical and genetic studies of stroke in the Zambian population. It is apparent that gender, age, ethnic tribe are important factors in the study for analysis of the candidate gene polymorphism for diseases. Other limitations of this study include lack of coverage from most African countries, particularly regarding the studies of the MTHFR C677T and the ACE I/D polymorphisms.

Conclusion

We found that the APOE ε3 allele and the I allele of the ACE were significantly high in our study population while there were low frequencies observed for the MTHFR 677 T and ACE D alleles. Our analysis of the APOE, MTHFR and ACE polymorphisms may provide valuable insight into the understanding of the disease risk in the Zambian population. However, our findings need to be compared with the clinical implication through additional studies within the Zambian population. The present study will serve as a template for future investigations of the prevalence of these genetic markers in larger population samples and their possible association with CAD, CVD and AD in the Zambian population.

Abbreviations

SSA:

Sub-Saharan Africa

APOE:

Apolipoprotein E

MTHFR:

Methylenetetrahydrofolate reductase

ACE I/D:

Angiotensin I-converting enzyme insertion/deletion

CVD:

Cerebrovascular disease

CAD:

Coronary artery disease

AD:

Alzheimer’s disease

DNA:

Deoxyribonucleic acid

HWE:

Hardy-Weinberg equilibrium

MDS:

Multidimensional Scaling.

References

  1. Connor MD, Walker R, Modi G, Warlow CP: Burden of stroke in black populations in sub-Saharan Africa. Lancet Neurol. 2007, 6: 269-78. 10.1016/S1474-4422(07)70002-9.

    Article  PubMed  Google Scholar 

  2. Masemola ML, Alberts M, Urdal P: Apolipoprotein E genotypes and their relation to lipid levels in a rural South African population Scandinavian. J Public Health. 2007, 35 (Suppl 69): 60-65.

    Google Scholar 

  3. Cross DS, Ivacic LC, Stefanski EL, McCarty CA: Population based allele frequencies of disease associated polymorphisms in the Personalized Medicine Research Project. BMC Genet. 2010, 11: 51-

    Article  PubMed  PubMed Central  Google Scholar 

  4. Eichner JE, Dunn ST, Perveen G, Thompson DM, Stewart KE, Stroehla BC: Apolipoprotein E polymorphism and cardiovascular disease: a HuGE review. Am J Epidemiol. 2002, 155 (6): 487-495. 10.1093/aje/155.6.487.

    Article  PubMed  Google Scholar 

  5. Minihane AM, Jofre-Monseny L, Olano-Martin E, Rimbach G: Apolipoprotein E genotype, cardiovascular risk and responsiveness to dietary fat manipulation. Proc Nutr Soc. 2007, 66 (2): 183-197. 10.1017/S0029665107005435.

    Article  PubMed  Google Scholar 

  6. Bersano A, Ballabio E, Bresolin N, Candelise L: Genetic polymorphisms for the study of multifactorial stroke. Hum Mutat. 2008, 29: 776-795. 10.1002/humu.20666.

    Article  PubMed  Google Scholar 

  7. Farrer LA, Cupples LA, Haines JL, Hyman B, Kukull WA, Mayeux R, Myers RH, Pericak-Vance MA, Risch N, van Duijn CM: Effects of age, sex, and ethnicity on the association between apolipoprotein E genotype and Alzheimer disease. A meta-analysis. APOE and Alzheimer Disease Meta-Analysis Consortium. JAMA. 1997, 278: 1349-1356. 10.1001/jama.1997.03550160069041.

    Article  PubMed  Google Scholar 

  8. Rigat B, Hubert C, Alhenc-Gelas F, Cambien F, Corvol P, Soubrier F: An insertion/deletion polymorphism in the angio-tensin I-converting enzyme gene accounting for half the variance of serum enzyme levels. J Clin Invest. 1990, 86: 1343-1346. 10.1172/JCI114844. CrossRef, PubMed, CSA

    Article  PubMed  PubMed Central  Google Scholar 

  9. Rigat B, Hubert C, Corvol P, Soubrier F: PCR detection of the insertion/deletion polymorphism of the human angiotensin converting enzyme gene (DCP1) (dipeptidy 1 carboxypeptidase 1). Nucleic Acids Res. 1992, 20: 14-33. CrossRef, PubMed

    Article  Google Scholar 

  10. Bonnardeaux A, Davies E, Jeunemaitre X, Féry I, Charru A, Clauser E, Tiret L, Cambien F, Corvol P, Soubrier F: Angiotensin II type 1 receptor gene polymorphisms in human essential hypertension. Hypertension. 1994, 24: 63-9. 10.1161/01.HYP.24.1.63.

    Article  PubMed  Google Scholar 

  11. Tiret L, Bonnardeaux A, Poirier O, Ricard S, Marques-Vidal P, Evans A, Kee F, Arveiler D, Luc G: Synergistic effects of angiotensin-converting enzyme and angiotensin-II type 1 receptor gene polymorphisms on risk of myocardial infarction. Lancet. 1994, 344: 910-3. 10.1016/S0140-6736(94)92268-3.

    Article  PubMed  Google Scholar 

  12. Schunkert H, Hense HW, Holmer SR, Stender M, Perz S, Keil U, Lorell BH, Riegger GA: Association between a deletion polymorphism of the angiotensin-converting-enzyme gene and left ventricular hypertrophy. N Engl J Med. 1994, 330: 1634-8. 10.1056/NEJM199406093302302.

    Article  PubMed  Google Scholar 

  13. Alvarez R, Reguero JR, Batalla A, Iglesias-Cubero G, Cortina A, Alvarez V: Angiotensin-converting enzyme and angiotensin II receptor 1 polymorphisms: association with early coronary disease. Cardiovasc Res. 1998, 40: 375-9. 10.1016/S0008-6363(98)00179-5.

    Article  PubMed  Google Scholar 

  14. Bøhn M, Berge KE, Bakken A, Erikssen J, Berg K: Insertion/deletion (I/D) polymorphism at the locus for angiotensin I-converting enzyme and myocardial infarction. Clin Genet. 1993, 44: 292-7.

    Article  PubMed  Google Scholar 

  15. Rutledge DR, Browe CS, Ross EA: Frequencies of the angiotensinogen gene and angiotensin I converting enzyme (ACE) gene polymorphisms in African Americans. Biochem Mol Biol Int. 1994, 34: 1271-1275. PubMed, CSA

    PubMed  Google Scholar 

  16. O’Donnell CJ, Lindpaintner K, Larson MG, Rao VS, Ordovas JM, Schaefer EJ: Evidence for association and genetic linkage of the angiotensin-converting enzyme locus with hypertension and blood pressure in men but not women in the Framingham Heart Study. Circulation. 1998, 97: 1766-72. 10.1161/01.CIR.97.18.1766.

    Article  PubMed  Google Scholar 

  17. Sagnella GA, Rothwell MJ, Onipinla AK, Wicks PD, Cook DG, Cappuccio PF: A population study of ethnic variations in the angiotensin converting enzyme I/D polymorphism: relationships with gender, hypertension and impaired glucose metabolism. J Hypertens. 1999, 17: 657-664. 10.1097/00004872-199917050-00009.

    Article  PubMed  Google Scholar 

  18. Kugaevskaia EV: Angiotensin converting enzyme and Alzheimer’s disease. Biomed Khim. 2013, 59 (1): 5-24.

    Article  PubMed  Google Scholar 

  19. Corbo RM, Scacchi R: Apolipoprotein E (APOE) allele distribution in the world. Is APOE*4 a ‘thrifty’ allele?. Ann Hum Genet. 1999, 63: 301-310. 10.1046/j.1469-1809.1999.6340301.x.

    Article  PubMed  Google Scholar 

  20. Fullerton SM, Clark AG, Weiss KM, Nickerson DA, Taylor SL, Stengard JH: Apolipoprotein E variation at the sequence haplotype level: implications for the origin and maintenance of a major human polymorphism. Am J Hum Genet. 2000, 67: 881-900. 10.1086/303070.

    Article  PubMed  PubMed Central  Google Scholar 

  21. Wilson PF, Myers RH, Larson MG, Ordovas JM, Wolf PM, Schaefer EJ: Apolipoprotein E alleles, dyslipidemia, and coronary heart disease. The Framingham Offspring Study. JAMA. 1994, 27 (2): 661-71.

    Google Scholar 

  22. Farrer LA, Cupples LA: Effects of age, sex, and ethnicity on the association between apolipoprotein E genotype and Alzheimer disease: a meta-analysis. J Am Med Assoc. 1997, 27 (8): 1349-58.

    Article  Google Scholar 

  23. Spotila LD, Jacques PF, Berger PB, Ballman KV, Ellison RC, Rozen R: Age dependence of the influence of methylenetetrahydrofolatereductase genotype on plasma homocysteine level. Am J Epidemiol. 2003, 158 (9): 871-877. 10.1093/aje/kwg234.

    Article  PubMed  Google Scholar 

  24. McIlroy SP, Dynan KB, Lawson JT, Patterson CC, Passmore AP: Moderately elevated plasma homocysteine, MethylenetetrahydrofolateReductase genotype, and risk for stroke vascular dementia, and Alzheimer disease in northern Ireland. Stroke. 2002, 33 (10): 2351-6. 10.1161/01.STR.0000032550.90046.38.

    Article  PubMed  Google Scholar 

  25. Wilcken B, Bamforth F, Li Z, Zhu H, Ritvanen A, Redlund M, Stoll C, Alembik Y, Dott B, Czeizel AE, Gelman-Kohan Z, Scarano G, Bianca S, Ettore G, Tenconi R, Bellato S, Scala I, Mutchinick OM, López MA, de Walle H, Hofstra R, Joutchenko L, Kavteladze L, Bermejo E, Martínez-Frías ML, Gallagher M, Erickson JD, Vollset SE, Mastroiacovo P, Andria G: Geographical and ethnic variation of the 677C>T allele of 5,10 methylenetetrahydrofolatereductase (MTHFR): findings from over 7000 newborns from 16 areas worldwide. J Med Genet. 2003, 40: 619-625. 10.1136/jmg.40.8.619.

    Article  PubMed  PubMed Central  Google Scholar 

  26. Singh PP, Singh M, Mastana SS: APOE distribution in world populations with new data from India and the UK. Ann Hum Biol. 2006, 33 (3): 279-308. 10.1080/03014460600594513.

    Article  PubMed  Google Scholar 

  27. New World Encyclopedia.http://www.newworldencyclopedia.org/entry/Zambia,

  28. Encyclopedia of the Nations.http://www.nationsencyclopedia.com/Africa/Zambia-HISTORY.html,

  29. Atadzhanov M, Mukomena PN, Lakhi S, Ross OA, Meschia JF: Stroke characteristics and outcomes of adult patients admitted to the University Teaching Hospital, Lusaka, Zambia. Open Gen Inter Med J. 2012, 5: 3-8. 10.2174/1874076601205010003.

    Article  Google Scholar 

  30. Mukomena PN, Lakhi S, Mwaba MH, Atadzhanov M: Familial aggregation of stroke (Literature review). Med J Zambia. in Press

  31. Cavalli-Sforza LL, Piazza A, Menozzi P, Mountain J: Reconstruction of human evolution: bringing together genetic, archeological, and linguistic data. Proc Natl Acad Sci U S A. 1988, 85: 6002-6006. 10.1073/pnas.85.16.6002.

    Article  PubMed  PubMed Central  Google Scholar 

  32. Wozniak MA, Faragher EB, Todd JA, Koram KA, Riley EM, Itzhaki RF: Does apolipoprotein E polymorphism influence susceptibility to malaria?. J Med Genet. 2003, 40: 348-351. 10.1136/jmg.40.5.348.

    Article  PubMed  PubMed Central  Google Scholar 

  33. Willis F, Graff-Radford N, Martin P, Lawson L, Adamson J, Epstein D, Parfitt F, Hufton M, O’brien PC: ApolipoproteinΕ4 Allele frequency in young Africans of Ugandan descent versus African Americans. J Natl Med Assoc. 2003, 95: 1-

    Google Scholar 

  34. Kalaria RN, Ogengo’o JA, Patel NB, Sayi JG, Kitinya JN, Chande HM, Matuja WB, Mtui EP, Kimani JK, Premkumar DRD, Koss E, Gateres S, Friedland RP: Evaluation of risk factors for Alzheimer’s disease in elderly east Africans. Elsevier. 1997, 44 (5): 573-577.

    Google Scholar 

  35. Zekraoui L, Lagarde JP, Raisonnier A, Gérard N, Aouizérate A, Lucotte G: High frequency of the apolipoprotein E*4 allele in African pygmies and most of the African populations in sub-Saharan Africa. Hum Biol. 1997, 69 (4): 575-581.

    PubMed  Google Scholar 

  36. They-They TP, Hamzi K, Moutawafik MT, Bellayou H, Messal M, Nadifi S: Prevalence of angiotensin-converting enzyme, methylenetetrahydrofolatereductase, Factor V Leiden, prothrombin and apolipoprotein E gene polymorphisms in Morocco. Ann Hum Biol. 2010, 37 (6): 767-777. 10.3109/03014461003738850.

    Article  PubMed  Google Scholar 

  37. Bahri R, Esteban E, Moral P, Hassine M, Hamda KB, Chaabani H: Apolipoprotein gene polymorphisms and plasma levels in healthy Tunisians and patients with coronary artery disease. Lipids Health Dis. 2008, 7: 46-10.1186/1476-511X-7-46.

    Article  PubMed  PubMed Central  Google Scholar 

  38. Sepehmia B, Kamboh MI, Adams-Campbell LL, Bunker CH, Majumder PP NM, Ferrel RE: Genetic studies of human apolipoproteins. XI. The effect of the apolipoprotein C-11 polymorphism on lipoprotein levels in Nigerian blacks. J Lipid Res. 1989, 30: 1349-1355.

    Google Scholar 

  39. Sandholzer C, Delport R, Vermaak H, Utermann G: High frequency of the apo epsilon 4 allele in Khoi San from South Africa. Hum Genet. 1995, 95 (1): 46-8.

    Article  PubMed  Google Scholar 

  40. Schneider JA, Rees DC, Liu Y, Clegg JB: Worldwide distribution of a common MethylenetetrahydrofolateReductase mutation (letter). Am J Hum Genet. 1998, 62: 1258-1260. 10.1086/301836.

    Article  PubMed  PubMed Central  Google Scholar 

  41. Shi M, Caprau D, Romitti P, Christensen K, Murray Jeffrey C: Genotype frequencies and linkage disequilibrium in the CEPH human diversity panel for variants in folate pathway genes MTHFR, MTHFD, MTRR, RFC1, and GCP2. Birth Defects Res (Part A). 2003, 67: 545-549. 10.1002/bdra.10076.

    Article  Google Scholar 

  42. Chillemi R, Angius A, Persico I, Sassu A, Prodi DA, Simpore J, Musumeci S: Methylenetetrahydrofolatereductase (MTHFR) from Mediterranean to sub-Saharan areas. Online J Biol Sci. 2005, 6 (1): 28-34.

    Google Scholar 

  43. Guéant-Rodriguez RM, Guéant JL, Debard R, Thirion S, Xiao Hong L, Bronowicki JP, Namour F, Chabi NW, Sanni A, Anello G, Bosco P, Romano C, Amouzou E, Heidy RA, BE S ́n, Romano A, Herbeth B, Guilland JC, Mutchinick OM: Prevalence of methylenetetrahydrofolatereductase677T and 1298C alleles and folate status: a comparative study in Mexican, West African, and European populations. Am J Clin Nutr. 2006, 83: 701-7.

    PubMed  Google Scholar 

  44. Rosenberg N, Murata M, Ikeda Y, Opare-Sem O, Zivelin A, Geffen E, Seligsohn U: The frequent 5,10-methylenetetrahydrofolate reductase C677T polymorphism is associated with a common haplotype in Whites, Japanese, and Africans. Am J Hum Genet. 2002, 70: 758-762. 10.1086/338932.

    Article  PubMed  PubMed Central  Google Scholar 

  45. Botto LD, Yang Q: 5,10-Methylenetetrahydrofolate reductase gene variants and congenital anomalies: a HuGE review. Am J Epidemiol. 2004, 151: 9-

    Google Scholar 

  46. Murry B, Vakha N, Achoubi N, Sachdeva MP, Saraswathy KN: APOE, MTHFR, LDLR and ACE polymorphisms among Angami and Lotha Naga populations of Nagaland, India. J Community Health. 2011, 36: 975-985. 10.1007/s10900-011-9397-z.

    Article  PubMed  Google Scholar 

  47. Comas D, Calafell F, Benchemsi N, Helal A, Lefranc G, Stoneking M, Batzer MA, Betranpetit J, Sajantila A: Alu insertion polymorphisms in NW Africa and the Iberian peninsula: evidence for a strong genetic boundary through the Gibraltar Straits. Hum Gen. 2000, 107: 312-319. 10.1007/s004390000370.

    Article  Google Scholar 

  48. Barley J, Blackwood A, Carter ND, Crews DE, Cruickshank JK, Jeffery S, Ogunlesi AO, Sagnella GA: Angiotensin gene converting enzyme insertion/deletion polymorphism: association with ethnic origin. J Hypertens. 1994, 12: 955-957.

    Article  PubMed  Google Scholar 

  49. Bayoumi RA, Simsek M, Yahya TM, Bendict S, Alhinai A, Al-Barwani H, Hassan MO: Insertion-deletion polymorphism in the angiotensin-converting enzyme (Ace) gene among Sudanese, Somalis, Emiratis, and Omanis. Hum Biol. 2006, 78: 103-108. 10.1353/hub.2006.0022.

    Article  PubMed  Google Scholar 

  50. Frossard PM, Obineche EN, Elshahat YI, Lestringant GG: Deletion polymorphism in the angiotensinconverting enzyme gene is not associated with hypertension in a Gulf Arab population. Clin Genet. 1997, 51: 211-213.

    Article  PubMed  Google Scholar 

  51. Vassilikioti S, Doumas M, Douma S, Petidis K, Karagiannis A, Balaska K: Angiotensin converting enzyme gene polymorphism is not related to essential hypertension in a Greek population. Am J Hypertens. 1996, 9: 700-702. 10.1016/0895-7061(95)00449-1.

    Article  PubMed  Google Scholar 

  52. Sprovieri SR, Sens YA: Polymorphisms of the renin-angiotensin system genes in Brazilian patients with lupus nephropathy. Lupus. 2005, 14: 356-362. 10.1191/0961203305lu2093oa.

    Article  PubMed  Google Scholar 

  53. Zhang YM, Zhang LY, Wang KQ: Distribution of angiotensin converting enzyme gene polymorphism among Northem Hans, Dahurs, and Ewenks. Acta Pharmacol Sin. 2001, 22: 747-750.

    PubMed  Google Scholar 

  54. Mohan KR, Julian FR, Michael JK: Deletion polymorphism in the gene for angiotensinconverting enzyme is a potent risk factor for myocardial infarction. Nature. 1992, 359: 641-644. 10.1038/359641a0.

    Article  Google Scholar 

  55. Saha N, Talmud PJ, Tay JSH, Humphries SE, Basair J: Lack of association of angiotensin-converting enzyme (ACE) gene insertion/deletion polymorphism with CAD in two Asian populations. Clin Genet. 1996, 50: 121-125.

    Article  PubMed  Google Scholar 

  56. Nomura H, Koni I, Michishita Y, Morise T, Takeda R: Angiotensin-converting enzyme gene polymorphism in haemodialysis patients. Lancet. 1994, 343: 482-483.

    Article  PubMed  Google Scholar 

  57. Lee EJD: Population genetics of the angiotensin-converting enzyme in Chinese. Br J Clin Pharmacol. 1994, 37: 212-214. 10.1111/j.1365-2125.1994.tb04264.x.

    Article  PubMed  PubMed Central  Google Scholar 

  58. Foy CA, McCormack LJ, Knowler WC, Barrett JH, Catto A: The angiotensin-I converting enzyme (ACE) gene I/D polymorphism and ACE levels in Pima Indians. Med Genet. 1996, 33: 336-337. 10.1136/jmg.33.4.336.

    Article  Google Scholar 

  59. Vargas-Alarcon G, Hemandez-Pacheco G, Rodriguez-Perez JM, Cardoso G, Posadas-Romero C: Angiotensin-converting enzyme gene (ACE) insertion/deletion polymorphism in Mexican populations. Hum Bi Bahnisch J, Bannister K, Faull R, Clarkson Aol. 2003, 75: 889-896.

    Google Scholar 

  60. Lester S, Heatley S, Bardy P, Bahnisch J, Bannister K, Faull R, Clarkson A: The DD genotype of the angiotensin-converting enzyme gene occurs in very low frequency in Australian Aboriginals. Nephrol Dial Transplant. 1999, 14: 887-890. 10.1093/ndt/14.4.887.

    Article  PubMed  Google Scholar 

  61. Campbell MC, Tishkoff SA: African genetic diversity: implications for human demographic history, modern human origins, and complex disease mapping. Annu Rev Genomics Hum Genet. 2008, 9: 403-433. 10.1146/annurev.genom.9.081307.164258.

    Article  PubMed  PubMed Central  Google Scholar 

  62. Lambert CA, Tishkoff SA: Genetic Structure in African populations: implications for human demographic history. Cold Spring Harb Symp Quant Biol. 2009, 74: 395-402. 10.1101/sqb.2009.74.053.

    Article  PubMed  PubMed Central  Google Scholar 

  63. Gerdes LU, Gerdes C, Hansen PS, Klausen IC, Faergeman O, Dyerberg J: The apolipoprotein polymorphism in Greenland Inuit in its global perspective. Hum Genet. 1996, 98 (5): 546-550. 10.1007/s004390050257.

    Article  PubMed  Google Scholar 

  64. Ehret C: An African classical age: Eastern and Southern Africa in world history, 1000 BC to AD 400. 1998, Charlottesville: University of Virginia Press

    Google Scholar 

  65. Franco RF, Araujo AG, Guerreiro JF, Elion J, Zago MA: Analysis of the 677C→ T mutation of the methylenetatrahydrofolatereductase gene in different ethnic groups. Thromb Haemost. 1998, 79: 119-121.

    PubMed  Google Scholar 

  66. Pepe G, Camacho Vanegas O, Giusti B, Brunelli T, Marcucci R, Attanasio M, Rickards O, De Stefano GF, Prisco D, Gensini GF, Abbate R: Heterogeneity in world distribution of the thermolabile C677T mutation in 5,10-methylenetetrahydrofolate reductase. (Letter). Am J Hum Genet. 1998, 63: 917-20. 10.1086/302015.

    Article  PubMed  PubMed Central  Google Scholar 

  67. Rosenblatt DS, Whitehead VM: Cobalamine and folate deficiency: acquired and hereditary disorders in children. Semin Hematol. 1999, 36: 19-34.

    PubMed  Google Scholar 

  68. Chillemi R, Zappacosta B, Simpore J, Persichilli S, Musumeci M, Musumeci S: Hyperhomocysteinemia in acute Plasmodium falciparum malaria: an effect of host-parasite interaction. Clin Chim Acta. 2004, 348 (1–2): 113-20.

    Article  PubMed  Google Scholar 

  69. Lucock M, Yates Z, Ng X, Veysey M, Blades B, Travers C, Lewis P, Sturm J, Roach P: Preliminary evidence for genetic selection of 677T-MTHFR by natural annual cycle of folate abundance. J Nutrigenet Nutrigenomics. 2008, 1: 24-29. 10.1159/000109872.

    Article  PubMed  Google Scholar 

  70. Romualdi C, Balding D, Nasidze IS, Risch G, Robichaux M, Sherry ST, Barbujani G: Patterns of human diversity, within and among continents, inferred from biallelic DNA polymorphisms. Genome Res. 2002, 12: 602-612. 10.1101/gr.214902.

    Article  PubMed  PubMed Central  Google Scholar 

  71. Staessen JA, Ginocchio G, Wang JG, Saavedra AP, Soubrier F, Vlietnick R, Fagard R: Genetic variability in the renin-angiotensin system: prevalence of alleles and genotypes. J Cardiovasc Risk. 1997, 4: 401-422. 10.1097/00043798-199710000-00013.

    Article  PubMed  Google Scholar 

  72. Harrap SB, Tzourio C, Cambien F, Poirier O, Raoux S, Chalmers J, Chapman N, Colman S, Leguennec S, MacMahon S, Neal B, Ohkubo T, Woodward M, PROGRESS Collaborative Group: The ACE gene I/D polymorphism is not associated with the blood pressure and cardiovascular benefits of ACE inhibition. Hypertension. 2003, 42: 297-303. 10.1161/01.HYP.0000088322.85804.96.

    Article  PubMed  Google Scholar 

  73. Gesang L, Liu G, Cen W, Qiu C, Zhouma C, Zhuang L, Ren D, Pincuo Z, Chan Y: Angiotensin converting enzyme gene polymorphism and its association with essential hypertension in a Tibetian population. Hypertens Res. 2002, 25: 481-485. 10.1291/hypres.25.481.

    Article  PubMed  Google Scholar 

  74. Doolan G, Nguyen L, Chung J, Ingles J, Semsarian C: Progression of left ventricular hypertrophy and the angiotensin-converting enzyme gene polymorphism in hypertrophiccardiomyopathy. Int J Cardiol. 2004, 96: 157-163. 10.1016/j.ijcard.2004.05.003.

    Article  PubMed  Google Scholar 

  75. Schut AFC, Bleumink GS, Stricker BH, Hofman A, Witteman JCM, Pols HAP, Deckers JW, Deinum J, van Duijn CM: Angiotensin converting enzyme insertion/deletion polymorphism and the risk of heart failure in hypertensive subjects. Eur Heart J. 2004, 25: 2143-2148. 10.1016/j.ehj.2004.08.026.

    Article  PubMed  Google Scholar 

  76. Gao XG, Huo Y, Teng ZP: Association studies of genetic polymorphism, environmental factors and their interaction in ischemic stroke. Neurosci Lett. 2006, 398: 172-177. 10.1016/j.neulet.2005.12.078.

    Article  PubMed  Google Scholar 

  77. Kurbanova D, Eliseyeva M: Genetic background of left ventricular hypertrophy in Uzbek hypertensive men. Soc Cardiol. 2010, 38: 466-472.

    Google Scholar 

  78. Kennon B, Petrie JR, Small M, Connell JMC: Angiotensin-converting enzyme gene and diabetes mellitus. Diabet Med. 1999, 16: 448-458. 10.1046/j.1464-5491.1999.00071.x.

    Article  PubMed  Google Scholar 

Download references

Acknowledgments

We thank Dr P. Kelly, Ms N. Shawa, and the Department of Internal Medicine UTH for supporting this study.

Author information

Authors and Affiliations

  1. Department of Internal Medicine, University of Zambia, P.O.Box 51237, Lusaka, Zambia

    Masharip Atadzhanov, Mwila H Mwaba, Patrice N Mukomena, Shabir Lakhi & Peter Mwaba

  2. Department of Neuroscience, Mayo Clinic, Jacksonville, FL, 32225, USA

    Sruti Rayaprolu & Owen A Ross

  3. Department of Neurology, Mayo Clinic, Jacksonville, FL, 32225, USA

    James F Meschia

Authors
  1. Masharip Atadzhanov
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Mwila H Mwaba
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Patrice N Mukomena
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Shabir Lakhi
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Peter Mwaba
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Sruti Rayaprolu
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. James F Meschia
    View author publications

    You can also search for this author in PubMed Google Scholar

  8. Owen A Ross
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Masharip Atadzhanov.

Additional information

Competing interests

The authors declare that they have no competing interests.

Authors’ contributions

MA has made substantial contribution to conception and design, drafted and revised the manuscript. MM has been involved in drafting and revising the manuscript, performed statistical analysis. PM participated in collection of data, participated in revising the manuscript. SL has been involved in revising the manuscript critically for important intellectual content. PBM has been involved in revising the manuscript critically for important intellectual content. SR participated in collecting of data. JFM has been involved in revising the manuscript critically for important intellectual content. OR has made substantial contribution to conception and design, carried out the molecular genetic studies, revised the manuscript, have given final approval of the version to be published. All authors read and approved the final manuscript.

Authors’ original submitted files for images

Below are the links to the authors’ original submitted files for images.

Authors’ original file for figure 1

Authors’ original file for figure 2

Rights and permissions

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited.

Reprints and permissions

About this article

Cite this article

Atadzhanov, M., Mwaba, M.H., Mukomena, P.N. et al. Frequency of APOE, MTHFR and ACE polymorphisms in the Zambian population. BMC Res Notes 7, 194 (2014). https://0-doi-org.brum.beds.ac.uk/10.1186/1756-0500-7-194

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://0-doi-org.brum.beds.ac.uk/10.1186/1756-0500-7-194

Keywords

BMC Research Notes

ISSN: 1756-0500

Contact us