Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2019 Nov 15;10(11):534-545.
doi: 10.4239/wjd.v10.i11.534.

Type 1 diabetes loci display a variety of native American and African ancestries in diseased individuals from Northwest Colombia

Natalia Gomez-Lopera  1 , Juan M Alfaro  1 , Suzanne M Leal  2 , Nicolas Pineda-Trujillo  3
Affiliations

Type 1 diabetes loci display a variety of native American and African ancestries in diseased individuals from Northwest Colombia

Natalia Gomez-Lopera et al. World J Diabetes. .

Abstract

Background: Type 1 diabetes (T1D) is a complex disease with a higher incidence in Europeans than other populations. The Colombians Living in Medellin (CLM) is admixed with ancestry contributions from Europeans, Native Americans (NAT) and Africans (AFR).

Aim: Our aim was to analyze the genetic admixture component at candidate T1D loci in Colombian individuals with the disease.

Methods: Seventy-four ancestry informative markers (AIMs), which tagged 41 T1D candidate loci/genes, were tested by studying a cohort of 200 Northwest Colombia diseased individuals. T1D status was classified by testing for glutamic acid decarboxylase (GAD-65 kDa) and protein tyrosine-like antigen-2 auto-antibodies in serum samples. Candidate loci/genes included HLA, INS, PTPN22, CTLA4, IL2RA, SUMO4, CLEC16A, IFIH1, EFR3B, IL7R, NRP1 and RNASEH1, amongst others. The 1,000 genome database was used to analyze data from 94 individuals corresponding to the reference CLM. As the data did not comply with a normal distribution, medians were compared between groups using the Mann-Whitney U-test.

Results: Both T1D patients and individuals from CLM displayed mainly European ancestry (61.58 vs 62.06) followed by Native American (27.34 vs 27.46) and to a lesser extent the AFR ancestry (10.28 vs 10.65) components. However, compared to CLM, ancestry of T1D patients displayed a decrease of NAT ancestry at gene EFR3B (24.30 vs 37.10) and an increase at genes IFIH1 (32.07 vs 14.99) and IL7R (52.18 vs 39.18). Also, for gene NRP1 (36.67 vs 0.003), we observed a non-AFR contribution (attributed to NAT). Autoimmune patients (positive for any of two auto-antibodies) displayed lower NAT ancestry than idiopathic patients at the MHC region (20.36 vs 31.88). Also, late onset patients presented with greater AFR ancestry than early onset patients at gene IL7R (19.96 vs 6.17). An association analysis showed that, even after adjusting for admixture, an association exists for at least seven such AIMs, with the strongest findings on chromosomes 5 and 10 (gene IL7R, P = 5.56 × 10-6 and gene NRP1, P = 8.70 × 10-19, respectively).

Conclusion: Although Colombian T1D patients have globally presented with higher European admixture, specific T1D loci have displayed varying levels of Native American and AFR ancestries in diseased individuals.

Keywords: Colombia; Genetic admixture; Idiopathic; Native American; Type 1 diabetes.

PubMed Disclaimer

Conflict of interest statement

Conflict-of-interest statement: None to declare.

Figures

Figure 1
Figure 1
Ancestry proportions of 200 type 1 diabetes patients from Colombia. EUR: European; NAT: Native American; AFR: African.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

References

    1. Morran MP, Vonberg A, Khadra A, Pietropaolo M. Immunogenetics of type 1 diabetes mellitus. Mol Aspects Med. 2015;42:42–60. - PMC - PubMed
    1. Onengut-Gumuscu S, Chen WM, Burren O, Cooper NJ, Quinlan AR, Mychaleckyj JC, Farber E, Bonnie JK, Szpak M, Schofield E, Achuthan P, Guo H, Fortune MD, Stevens H, Walker NM, Ward LD, Kundaje A, Kellis M, Daly MJ, Barrett JC, Cooper JD, Deloukas P Type 1 Diabetes Genetics Consortium, Todd JA, Wallace C, Concannon P, Rich SS. Fine mapping of type 1 diabetes susceptibility loci and evidence for colocalization of causal variants with lymphoid gene enhancers. Nat Genet. 2015;47:381–386. - PMC - PubMed
    1. Barrett JC, Clayton DG, Concannon P, Akolkar B, Cooper JD, Erlich HA, Julier C, Morahan G, Nerup J, Nierras C, Plagnol V, Pociot F, Schuilenburg H, Smyth DJ, Stevens H, Todd JA, Walker NM, Rich SS Type 1 Diabetes Genetics Consortium. Genome-wide association study and meta-analysis find that over 40 loci affect risk of type 1 diabetes. Nat Genet. 2009;41:703–707. - PMC - PubMed
    1. Pineda-Trujillo N, Rodríguez-Acevedo A, Rodríguez A, Ruíz-Linares A, Bedoya G, Rivera A, Alfaro JM. RNASEH1 gene variants are associated with autoimmune type 1 diabetes in Colombia. J Endocrinol Invest. 2018;41:755–764. - PubMed
    1. Patterson C, Guariguata L, Dahlquist G, Soltész G, Ogle G, Silink M. Diabetes in the young - a global view and worldwide estimates of numbers of children with type 1 diabetes. Diabetes Res Clin Pract. 2014;103:161–175. - PubMed