👩‍🔬 leapdna

← Back to Explore

Guarani Ñandeva (Brazilian Amerindian), Brazil

Study statistics

Loci
21 Autosomal STRs
Allele type
Unknown
Sample size
71
Population
Guarani Ñandeva (Brazilian Amerindian)
More studies with this population
Location
Southern Brazil
More studies with this location

Download

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 70 0.179 1.250 0.600 0.643 0.580 0.821 0.291 0.150
D10S1248 71 0.162 1.610 0.690 0.678 0.620 0.838 0.413 0.682
D12S391 71 0.182 1.690 0.704 0.672 0.620 0.818 0.435 0.207
D13S317 71 0.068 1.970 0.746 0.796 0.770 0.932 0.504 0.948
D16S539 71 0.149 1.570 0.676 0.695 0.670 0.851 0.399 0.009
D18S51 71 0.091 1.310 0.620 0.761 0.730 0.909 0.315 0.421
D19S433 71 0.052 2.220 0.775 0.843 0.820 0.948 0.553 0.136
D1S1656 71 0.043 2.960 0.831 0.859 0.840 0.957 0.658 0.488
D21S11 71 0.119 2.250 0.775 0.708 0.680 0.881 0.558 0.967
D22S1045 71 0.343 1.060 0.521 0.491 0.410 0.657 0.213 0.422
D2S1338 71 0.066 1.780 0.718 0.804 0.780 0.934 0.457 0.360
D2S441 71 0.356 0.890 0.437 0.423 0.390 0.644 0.138 0.950
D3S1358 71 0.151 1.220 0.592 0.673 0.630 0.849 0.281 0.263
D5S818 71 0.151 1.310 0.620 0.673 0.620 0.849 0.315 0.230
D7S820 71 0.226 1.420 0.648 0.643 0.580 0.774 0.352 0.014
D8S1179 71 0.122 1.540 0.676 0.727 0.680 0.878 0.392 0.129
FGA 71 0.053 2.220 0.775 0.835 0.810 0.947 0.553 0.385
SE33 71 0.032 2.730 0.817 0.892 0.880 0.968 0.631 0.105
TH01 71 0.301 1.110 0.549 0.537 0.470 0.699 0.234 0.611
TPOX 71 0.177 1.380 0.634 0.647 0.600 0.823 0.340 0.790
vWA 71 0.186 1.080 0.535 0.645 0.580 0.814 0.220 0.009

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 0.606
7 0.077 0.338 0.007 0.303
8 0.007 0.014 0.021 0.014 0.014 0.282
9 0.31 0.472 0.106 0.014 0.014 0.021
10 0.143 0.021 0.049 0.028 0.739 0.035 0.085 0.042 0.021
11 0.286 0.19 0.183 0.007 0.162 0.444 0.486 0.486
11.3 0.007
12 0.5 0.021 0.225 0.197 0.218 0.021 0.021 0.028 0.042 0.331 0.07 0.014 0.19
12.2 0.056
13 0.071 0.12 0.092 0.085 0.19 0.204 0.077 0.007 0.035 0.056 0.239 0.014
13.2 0.106
14 0.43 0.077 0.366 0.183 0.12 0.056 0.077 0.401 0.007
14.2
15 0.338 0.077 0.204 0.155 0.641 0.493 0.218 0.035
15.2 0.134
15.3
16 0.092 0.021 0.085 0.19 0.31 0.239 0.014 0.19 0.38
16.2 0.007
16.3 0.113
17 0.014 0.12 0.035 0.042 0.324 0.134 0.07 0.437
17.3 0.204
18 0.07 0.007 0.077 0.049 0.007 0.12 0.134
18.3 0.056
19 0.423 0.099 0.007 0.141 0.141 0.042
20 0.373 0.12 0.077
20.3
21 0.063 0.014 0.07 0.028
22 0.028 0.19 0.042
23 0.021 0.155 0.127
24 0.007 0.007 0.211
24.2
25 0.014 0.204
25.2
26 0.19
26.2 0.085
27 0.007
27.2 0.056
28
28.2 0.113
29 0.12
29.2
30 0.472
30.2 0.007 0.028
31 0.014
31.2 0.077
32.2 0.176 0.021
33.2 0.134 0.007
35.1
36
43.2
53
63
93 0.063

Locus histograms

CSF1PO

D10S1248

D12S391

D13S317

D16S539

D18S51

D19S433

D1S1656

D21S11

D22S1045

D2S1338

D2S441

D3S1358

D5S818

D7S820

D8S1179

FGA

SE33

TH01

TPOX

vWA