A polymorphism in the haptoglobin, haptoglobin related protein locus is associated with risk of human sleeping sickness within Cameroonian populations
| Autor: | Ofon, Elvis, Noyes, Harry, Mulindwa, Julius, Ilboudo, Hamidou, Simuunza, Martin, Eboo, Vincent, Njiokou, Flobert, Koffi, Mathurin, Bucheton, Bruno, Fogue, Pythagore, Hertz-Fowler, Christiane, MacLeod, Annette, Simo, Gustave, Grp, TrypanoGEN Res, Consortium, H3Africa |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Male
0301 basic medicine Heredity Trypanosoma brucei gambiense Biochemistry Geographical Locations Gene Frequency Risk Factors Zoonoses Medicine and Health Sciences Cameroon Child Aged 80 and over Protozoans Genetics biology lcsh:Public aspects of medicine Haptoglobin Neglected Diseases Eukaryota Middle Aged 3. Good health Genetic Mapping Infectious Diseases Female Research Article Neglected Tropical Diseases Adult Trypanosoma Genotyping medicine.medical_specialty lcsh:Arctic medicine. Tropical medicine Adolescent Genotype lcsh:RC955-962 Variant Genotypes Locus (genetics) Single-nucleotide polymorphism Research and Analysis Methods Polymorphism Single Nucleotide African Trypanosomiasis Molecular Genetics Young Adult 03 medical and health sciences Antigens Neoplasm Trypanosomiasis Molecular genetics Parasitic Diseases medicine Humans SNP Genetic Predisposition to Disease Molecular Biology Techniques Molecular Biology Alleles Genetic Association Studies Aged Protozoan Infections Plasma Proteins Haptoglobins Organisms Public Health Environmental and Occupational Health Biology and Life Sciences Proteins lcsh:RA1-1270 Tropical Diseases Parasitic Protozoans Minor allele frequency Trypanosomiasis African 030104 developmental biology Genetic Loci Case-Control Studies Asymptomatic Diseases People and Places Africa Immunology biology.protein Asymptomatic carrier |
| Zdroj: | PLOS NEGLECTED TROPICAL DISEASES PLoS Neglected Tropical Diseases, Vol 11, Iss 10, p e0005979 (2017) PLoS Neglected Tropical Diseases |
| ISSN: | 1935-2727 |
| Popis: | Background Human African Trypanosomiasis (HAT) is a neglected disease targeted for elimination as a public health problem by 2020. Elimination requires a better understanding of the epidemiology and clinical evolution of HAT. In addition to the classical clinical evolution of HAT, asymptomatic carriers and spontaneous cure have been reported in West Africa. A genetic component to human susceptibility to HAT has been suggested to explain these newly observed responses to infection. In order to test for genetic associations with infection response, genetic polymorphism in 17 genes were tested (APOL1, IL1B, IL4, IL4R, IL6, IL8, IL12B, IL12RB1, IL10, TNFA, INFG, MIF, HLA-G, HLA-A, HP, HPR and CFH). Methodology A case-control study was performed on 180 blood samples collected from 56 cases and 124 controls from Cameroon. DNA was extracted from blood samples. After quality control, 25 samples (24 controls and 1 case) were eliminated. The genotyping undertaken on 155 individuals including 55 cases and 100 controls were investigated at 96 loci (88 SNPs and 8 indels) located on 17 genes. Associations between these loci and HAT were estimated via a case-control association test. Results Analyses of 64 SNPs and 4 indels out of 96 identified in the selected genes reveal that the minor allele (T) of rs8062041 in haptoglobin (HP) appeared to be protective against HAT (p = 0.0002395, OR 0.359 (CI95 [0.204–0.6319])); indicating higher frequency in cases compared to controls. This minor allele with adjusted p value of 0.0163 is associated with a lower risk (protective effect) of developing sleeping sickness. Conclusion The haptoglobin related protein HPR and HP are tightly linked and both are duplicated in some people and may lead to higher activity. This increased production could be responsible of the protection associated with rs8062041 even though this SNP is within HP. Author summary Human African trypanosomiasis (HAT) or sleeping sickness is a neglected tropical disease targeted for elimination by 2020. This elimination requires a better understanding of the epidemiology and clinical evolution of this disease. Beside the classical clinical evolution, asymptomatic carriers, seropositive and spontaneous cure of infected persons have been reported in West Africa. Arguments in favor of human genetic susceptibility to HAT have been raised to explain this variability in clinical presentation. This study investigated the genetic polymorphism of 17 genes between controls and sleeping sickness patients in Southern Cameroon in order to improve our knowledge of human susceptibility to trypanosome infections. We identified single nucleotide polymorphisms and indels in 17 selected genes involved in immune responses and carried out a case-control candidate gene association study and demonstrated differences between variants associated with the disease. From these genes, only haptoglobin (HP) at the SNP rs8062041 was found to have polymorphisms which were strongly associated with trypanosomiasis. The minor allele (T) at this SNP position appeared to be protective against HAT (p = 0.0002395, OR 0.359 (CI95 [0.204–0.6319])) reducing the risk of developing disease approximately threefold. The haptoglobin related protein (HPR) is adjacent to HP and is a component of the Trypanolytic factor that kills trypanosomes. The HP and HPR locus is duplicated in some people. The rs8062041 variant may be associated with this duplication and it is possible that increased production of HPR is the cause of the protection associated with rs8062041. The results reported here will contribute to the knowledge of the role of human genetics in disease progression, and thus lead to the identification of novel biomarkers which could involve development of new diagnostics, treatments and intervention strategies. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|