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Kaingang, Brazil (Ivai)

Study statistics

Loci
21 Autosomal STRs
Allele type
Unknown
Sample size
61
Location
Ivai, Brazil
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Bibliographic information

Date published
Feb. 12, 2022
Title
Population structure and forensic genetic analyses in Guarani and Kaingang Amerindian populations from Brazil
Authors
Claudia Marina Schellin-Becker, Verónica Calonga-Solís, Marcelo Malaghini, Luiza Rauen Sabbag, Maria Luiza Petzl-Erler, Danillo G Augusto, and Danielle Malheiros
Journal
Forensic Science International: Genetics
Abstract

When DNA profile comparisons between a crime scene trace and a reference sample generate correspondence, the match probability has to be estimated, so that evaluation of the strength of the forensic DNA evidence can be made. The random match probability estimations require information on allele frequencies and an adjustment factor, referred to as theta (θ) or Fst, a co-ancestry correction factor for subpopulation effects. The θ value has been standardized for urban and isolated populations, but inconsistencies have been reported when it is specifically calculated for smaller and isolated populations, including Amerindian populations. Notably, attempts to characterize forensic markers of these minor populations have been extensively limited and more conservative estimates of the correction factor may be generated for each of them. Therefore, we estimate allele frequencies of 21 autosomal STR markers used for forensic testing and calculated relevant forensic parameters for the set. In addition, we featured the possible structure of five Brazilian Amerindian populations that have been genetically isolated for centuries so we could obtain the appropriate θ value for them. The sample consisted of 319 individuals: (1) 121 Kaingang, from two communities: Ivaí (KIV=61) and Rio das Cobras (KRC=60); and (2) 198 Guaranis from three communities: Mbya from Rio das Cobras (GRC=51), Guarani Ñandeva (GND=71) and Guarani Kaiowá (GKW=76). Between Guarani populations low (Rst=0.0402, p < 10−4) to high (Rst=0.1557, p < 10−5) differentiation was found. Regarding Guarani and Kaingang populations, intermediate (Rst=0.0590, p < 10−5) to high (Rst=0.1604, p < 10−5) differentiation was found. The two Kaingang populations showed very low differentiation between them (Rst=0.0017, p = 0.27), which justifies the union of both genetic data for forensic databases and calculations. The combined power of discrimination (PD) and the combined power of exclusion (PE) were calculated for each population, demonstrating the usefulness of this set of markers in forensic and kinship analysis regarding these populations. Considering the demographic heterogeneity of Amerindian populations in general, the Fst mean value (0.03) was evaluated regarding 43 different indigenous populations from the Americas, including Guaranis and Kaingangs. This result confirms the adequacy of the standardized θ value for the forensic random match probability estimations involving Amerindian populations.

Forensic parameters

Forensic parameters for each locus as reported by the authors.
Locus # MP PI Hobs Hexp PIC PD PE HWE
CSF1PO 61 0.261 1.330 0.623 0.592 0.510 0.739 0.319 0.515
D10S1248 61 0.304 1.090 0.541 0.536 0.440 0.696 0.226 1.000
D12S391 60 0.141 1.430 0.650 0.689 0.640 0.859 0.355 0.746
D13S317 61 0.087 1.910 0.738 0.776 0.740 0.913 0.489 0.433
D16S539 61 0.132 2.210 0.770 0.740 0.700 0.868 0.552 0.181
D18S51 61 0.077 1.610 0.689 0.804 0.780 0.923 0.411 0.033
D19S433 61 0.102 2.540 0.803 0.759 0.720 0.898 0.605 0.622
D1S1656 61 0.105 5.080 0.902 0.788 0.760 0.895 0.799 0.023
D21S11 61 0.098 1.940 0.738 0.751 0.730 0.902 0.496 0.435
D22S1045 61 0.309 1.000 0.492 0.491 0.430 0.691 0.188 0.783
D2S1338 60 0.084 2.310 0.783 0.800 0.770 0.916 0.568 0.354
D2S441 61 0.320 1.090 0.541 0.530 0.430 0.680 0.226 0.613
D3S1358 61 0.246 1.330 0.623 0.582 0.520 0.754 0.319 0.223
D5S818 61 0.146 1.390 0.639 0.724 0.680 0.854 0.341 0.002
D7S820 61 0.141 1.390 0.639 0.696 0.650 0.859 0.341 0.236
D8S1179 61 0.166 2.540 0.803 0.714 0.670 0.834 0.605 0.061
FGA 61 0.070 2.350 0.787 0.804 0.780 0.930 0.575 0.359
SE33 60 0.051 3.330 0.850 0.859 0.840 0.949 0.695 0.123
TH01 61 0.257 1.390 0.639 0.609 0.530 0.743 0.341 0.085
TPOX 61 0.155 1.350 0.623 0.676 0.630 0.845 0.327 0.488
vWA 61 0.399 1.220 0.590 0.513 0.400 0.601 0.279 0.275

Allele frequencies

CSF1PO D10S1248 D12S391 D13S317 D16S539 D18S51 D19S433 D1S1656 D21S11 D22S1045 D2S1338 D2S441 D3S1358 D5S818 D7S820 D8S1179 FGA SE33 TH01 TPOX vWA
5
6 0.115
7 0.287 0.418
8 0.041 0.418
9 0.303 0.32 0.189 0.123 0.008
10 0.107 0.057 0.23 0.385 0.295 0.057 0.082
11 0.361 0.098 0.295 0.057 0.566 0.369 0.434 0.156
11.3
12 0.516 0.008 0.156 0.131 0.033 0.008 0.008 0.008 0.008 0.148 0.107 0.213 0.344
12.2 0.074
13 0.016 0.041 0.295 0.025 0.148 0.164 0.107 0.008 0.426
13.2 0.369
14 0.566 0.09 0.311 0.033 0.131 0.025 0.041 0.221
14.2
15 0.377 0.049 0.246 0.164 0.664 0.574 0.082 0.008
15.2 0.107
15.3
16 0.008 0.058 0.197 0.049 0.254 0.238 0.008 0.533
16.2
16.3
17 0.008 0.172 0.016 0.258 0.18 0.133 0.451
17.3 0.352
18 0.058 0.074 0.058 0.025 0.008
18.3 0.172
19 0.458 0.016 0.158 0.074 0.158 0.008
20 0.283 0.142 0.008 0.092
20.3
21 0.117 0.131 0.008
22 0.117 0.074
23 0.017 0.267 0.172
24 0.328
24.2
25 0.172
25.2 0.092
26 0.025
26.2 0.033
27 0.057
27.2 0.225
28 0.049
28.2 0.167
29 0.09
29.2 0.025
30 0.426
30.2 0.025
31
31.2 0.049
32.2 0.148
33.2 0.172
35.1
36 0.008
43.2 0.016
53 0.008
63
93 0.451

Locus histograms

CSF1PO

D10S1248

D12S391

D13S317

D16S539

D18S51

D19S433

D1S1656

D21S11

D22S1045

D2S1338

D2S441

D3S1358

D5S818

D7S820

D8S1179

FGA

SE33

TH01

TPOX

vWA