EVALUATION OF GENETIC POPULATION

Evaluation of Genetic Population

Evaluation of Genetic Population

Introduction

The study is related to allele distributions for 6 non-Combined DNA Index System loci that are D4S2366, D3S1744, D8S1110, D12S1090, D13S765 and D10S2325. These non-Combined DNA Index System loci are determined in sample populations of Trinidadian, Hispanic, Caucasian, African American, Jamaican and Bahamian.

Methodology

The particular focus of the study is to develop short tandem repeat (STR) markers which are not linked with the non-Combined DNA Index System loci is growing among forensic practitioners. The study develops a multiplex system in which six short tandem repeat that are D4S2366, D3S1744, D8S1110, D12S1090, D13S765 and D10S2325 could be amplified in a chain reaction. The samples of DNA are taken from different populations groups that include Trinidadian, Hispanic, Caucasian, African American, Jamaican and Bahamian which are analyzed using this 6 STR.

Results and Discussion

The observed percentage of allele distributions for all 6 loci is mentioned in the given Table 1. The expected and observed homozygosities, exact test for the departures from HWE, discrimination probability (PD), and probability of exclusion (PE) are also mentioned in the table. It is observed that all loci are extremely polymorphic in every sample of the populations with the loci D3S1744 in Bahamian (73.5%), D13S765 in Hispanic (52.9%), D4S2366 in Hispanic (68.4%), in Jamaican (72.1%) and D10S2325 in Caucasian (67.7%) have the lowest observed heterozygosities. Besides it, it is also observed from the table that the loci D10S2325 in Bahamians (74.5%), in African American (75.8%), D8S1110 in African American (85.4%) and D3S1744 in Jamaicans (81.7%), in Bahamians (80.8%) showing the highest heterozygosities. In addition to this, the most discriminating in all sample populations loci are D10S2325, D8S1110 and D3S1744. Moreover, it is also observed that among Bahamians and Caucasian, the D4S2366 loci is the least discriminating loci, at the same time as the D13S765 loci show indications of less discriminating loci with the populations of African American.

Moreover, it is also observed that the exact test shows that the loci which departed significantly from Hardy-Weinberg expectations include D8S1110 (p = 0.05, Bahamian); D10S2325 (p = 0.09, Jamaican); D12S1090 (p = 0.011, African American); and D13S765 (p = 0.043, Jamaican). In addition to this, it is observed that after considering the Bonferroni correction for the 6 non-Combined DNA Index System loci which are analyzed, the observations are not expected to be significant.

Table 1- Allele Distributions for 6 non-CODIS loci in six population groups

 

Caucasian

Hispanic

Jamaican

African American

Trinidad

Bahamian

D3S1744

(N = 90)

(N = 180)

(N = 170)

(N = 140)

(N = 120)

(N = 120)

< 18

0.09

0

0.863

0.368

0

1.364

18

3.151

0.336

0

0.923

1.34

0.09

18.2

0.09

0.09

2.152

0.923

0.09

1.364

19

5.702

7.972

6.791

5.368

5.715

5.822

19.2

0.09

0

0.863

0.368

0.09

0

20

14.631

7.233

4.729

7.312

9.465

7.415

20.2

0.345

0.336

0

0

0

0.09

21

17.437

13.144

7.564

12.59

10.09

11.236

21.2

0.09

0.336

0.09

0

0

0.408

22

18.968

17.824

18.904

22.59

16.965

14.421

22.2

1.11

0.583

0

0.646

0.09

0

22.3

0

0

0

0

0.09

0.408

23

15.906

14.129

19.678

12.59

16.34

18.243

23.2

0.09

0.829

0.09

0.09

0.09

0

24

13.866

12.652

14.523

18.701

20.715

20.154

24.2

0.09

0.09

0.348

0.09

0.09

0.09

24.3

0.09

0.09

0.348

0.09

0.09

0

25

6.978

13.883

11.688

10.09

10.715

9.644

26

1.876

8.464

4.214

3.701

4.465

3.275

27

1.11

3.292

5.245

2.312

1.965

5.186

28

0

0.336

1.636

1.757

1.34

1.045

29

0

0

0.863

0.646

0.715

0.727

30

0

0

0.09

0.368

0.09

0

> 30

0.09

0.09

1.121

0.368

1.34

0.727

Homozygosity (Obs.)

21.2 %

21.3 %

18.3 %

21.8 %

26.5 %

19.2 %

Homozygosity (Exp.)

22.8 %

21.0 %

21.3 %

22.4 %

21.8 %

21.5 %

(p)

0.617

0.99

0.286

0.884

0.297

0.468

Exact Test

0.36

0.725

0.38

1.085

0.925

1.02

PD

1.049

1.059

1.052

1.054

1.052

1.057

PE

0.807

0.842

0.84

0.818

0.823

0.834

 

Caucasian

Hispanic

Jamaican

African American

Trinidad

Bahamian

D4S2366

(N = 230)

(N = 165)

(N = 250)

(N = 175)

(N = 67)

(N = 148)

11

0

0.316

0.48

0.348

0.658

0.996

13

0.58

0

0.89

0.626

0.658

2.848

14

10.274

6.228

7.447

6.737

8.894

6.243

15

11.294

7.705

22.816

23.681

14.188

15.193

16

20.223

36.031

29.168

27.014

29.482

26.305

17

26.346

22.237

18.308

18.403

26.541

20.749

18

22.264

19.528

13.185

13.681

13.599

18.28

19

8.488

7.213

5.398

7.292

4.776

7.169

20

1.09

1.302

2.324

2.848

1.835

2.848

21

0.07

0.07

0.685

0.07

0.07

0.07

Homozygosity (Obs.)

29.4 %

31.6 % ...