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Guarani Kaiowá (Brazilian Amerindian), Brazil

Study statistics

Loci
21 Autosomal STRs
Allele type
Unknown
Sample size
76
Population
Guarani Kaiowá (Brazilian Amerindian)
More studies with this population
Location
Southern 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 76 0.204 1.580 0.684 0.643 0.580 0.796 0.404 0.285
D10S1248 76 0.204 1.150 0.566 0.626 0.550 0.796 0.252 0.263
D12S391 76 0.122 2.110 0.763 0.733 0.700 0.878 0.533 0.063
D13S317 76 0.098 1.650 0.697 0.752 0.710 0.902 0.424 0.552
D16S539 76 0.246 1.040 0.513 0.552 0.520 0.754 0.205 0.264
D18S51 76 0.088 2.110 0.763 0.783 0.750 0.912 0.533 0.589
D19S433 76 0.094 2.530 0.803 0.757 0.720 0.906 0.604 0.995
D1S1656 76 0.086 1.730 0.711 0.761 0.730 0.914 0.445 0.329
D21S11 76 0.116 1.930 0.737 0.735 0.700 0.884 0.493 0.560
D22S1045 76 0.348 1.280 0.605 0.547 0.450 0.652 0.304 0.159
D2S1338 76 0.078 2.710 0.816 0.807 0.780 0.922 0.629 0.082
D2S441 76 0.429 0.810 0.382 0.356 0.330 0.571 0.103 1.000
D3S1358 76 0.179 2.110 0.763 0.681 0.630 0.821 0.533 0.235
D5S818 76 0.300 1.090 0.539 0.523 0.470 0.700 0.224 0.223
D7S820 76 0.217 1.730 0.711 0.642 0.580 0.783 0.445 0.053
D8S1179 76 0.155 2.240 0.776 0.682 0.640 0.845 0.556 0.647
FGA 76 0.076 2.710 0.816 0.801 0.770 0.924 0.629 0.489
SE33 76 0.028 4.220 0.882 0.897 0.890 0.972 0.758 0.526
TH01 76 0.276 0.860 0.421 0.546 0.480 0.724 0.127 0.001
TPOX 76 0.192 1.280 0.605 0.639 0.580 0.808 0.304 0.643
vWA 76 0.139 1.580 0.684 0.707 0.650 0.861 0.404 0.777

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 0.605
7 0.039 0.25 0.283
8 0.007 0.039 0.007 0.289
9 0.007 0.224 0.625 0.079 0.007 0.007 0.007
10 0.23 0.013 0.026 0.789 0.02 0.138 0.138
11 0.48 0.368 0.158 0.007 0.007 0.007 0.007 0.125 0.638 0.474 0.474
11.3
12 0.27 0.204 0.178 0.211 0.02 0.072 0.013 0.336 0.046 0.007 0.23
12.2 0.007
13 0.013 0.388 0.138 0.007 0.033 0.395 0.02 0.007 0.007 0.112
13.2 0.072
14 0.461 0.013 0.322 0.178 0.033 0.007 0.007 0.053 0.487
14.2 0.013
15 0.066 0.204 0.145 0.026 0.533 0.428 0.217 0.053
15.2 0.171
15.3
16 0.086 0.007 0.007 0.013 0.375 0.408 0.007 0.336 0.151 0.283
16.2
16.3 0.118
17 0.145 0.086 0.046 0.289 0.138 0.118 0.342
17.3 0.27
18 0.053 0.072 0.007 0.046 0.046 0.125 0.303
18.3 0.039
19 0.211 0.118 0.138 0.164 0.066
20 0.428 0.158 0.039 0.007
20.3 0.007
21 0.066 0.013 0.072
22 0.026 0.132 0.02
23 0.178 0.224 0.164
24 0.026 0.013 0.092
24.2
25 0.013 0.257
25.2 0.026
26 0.276
26.2
27 0.039
27.2 0.079
28
28.2 0.066
29 0.053
29.2 0.02
30 0.336
30.2 0.007 0.013
31
31.2 0.059 0.046
32.2 0.283 152.0 0.007
33.2 0.257 0.013
35.1 0.007
36
43.2
53 0.007
63 0.007
93 0.086

Locus histograms

CSF1PO

D10S1248

D12S391

D13S317

D16S539

D18S51

D19S433

D1S1656

D21S11

D22S1045

D2S1338

D2S441

D3S1358

D5S818

D7S820

D8S1179

FGA

SE33

TH01

TPOX

vWA