blind testing and evaluation of a comprehensive dna ...prediction results methods introduction blind...
TRANSCRIPT
Prediction Results
Methods
Introduction
Blind Testing and Evaluation of a Comprehensive DNA Phenotyping System
Rachel Wiley1, Xiangpei Zeng1, Bobby Larue1, Ellen M. Greytak2, Steven Armentrout2, Bruce Budowle1,3
1) Institute of Applied Genetics, Department of Molecular and Medical Genetics, University of North Texas Health Science Center (UNTHSC), Forth Worth, TX;
2) Parabon NanoLabs, Inc., Reston, VA; 3) Center of Excellence in Genomic Medicine Research (CEGMR), King Abdulaziz University, Jeddah, Saudi Arabia
Predictions Vs. Actual Appearance DNA phenotyping refers to the prediction of ancestry and/or physical appearance from DNA. In forensics, these predictions have the potential to generate new investigative leads in cases
where DNA does not match a known suspect or a database, and to discover more information about unidentified remains. In this study,
the Parabon® Snapshot™ DNA Phenotyping System, which predicts detailed biogeographic ancestry, pigmentation (eye color,
hair color, skin color, and freckling), and face morphology, was evaluated in a blind experiment. This study represents the first public blind evaluation of a comprehensive DNA phenotyping
system, including side-by-side comparisons of the composite images and the actual photographs of each subject.
0% 50% 100%
Blue Green Hazel Brown Black
0% 50% 100%
Blond Brown Black
Skin Color
VF
air
Fair
LtB
rn
Bro
wn
DkB
rn
Eye Color
Gre
en
Bro
wn
Hair Color
Blo
nd
B
row
n
Bla
ck
-Red
+
Red
Freckles
Zero
F
ew
S
om
e
Many
Composite Actual
Width Height Depth Regional Ancestry
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This study demonstrated the predictive performance of the Parabon Snapshot DNA Phenotyping system. Overall, the predicted features were consistent with the actual phenotypes:
skin color, eye color, hair color, freckling, and ancestry. This phase of the study serves as a preliminary assessment of Level 1 detail so
that strengths and limitations could be identified to set up a more in-depth analysis of face morphology in phase 2.
Conclusions
Brown*
0%
20%
40%
60%
80%
100%
23
- A
fAm
24
- A
fAm
16
- J
am
aic
a
8 -
Ind
ia
21
- Ind
ia
22
- N
Ind
ia
19
- S
Ind
ia
2 -
Chin
a
12
- C
hin
a
3 -
Jap
an
18
- S
Chin
a
17
- S
Chin
a
14
- E
uro
pe
1 -
Euro
pe
7 -
Euro
pe
9 -
Euro
pe
10
- E
uro
pe
15
- E
uro
pe
20
- E
uro
pe
25
- E
uro
pe
5 -
Euro
pe
6 -
Euro
pe
4 -
Euro
pe
13
- L
eb
anon
Pre
dic
ted
An
ce
str
y
Subject ID – Self-Reported Ancestry
MidEast-W MidEast-N Europe-W Europe-SW Europe-SE Europe-S Europe-NE Europe-N EAsia-SE EAsia-Japan EAsia-Cen CAsia-S CAsia-NE CAsia-N CAsia-E Africa-W
Green*
Brown*
Blond*
°
§
§
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4
5
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10
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24
25
VFair Fair LtBrn Brown DkBrn
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Fair*
Fair*
Predicted Phenotype Consistencies vs. Actual Phenotype 96% 96% 92% Skin Color Eye Color Hair Color
Su
bje
ct
ID N
um
be
r
• 24 subjects recruited for phenotypic and ancestral diversity by the University of North Texas Health Science Center (UNTHSC)
• 25 anonymous DNA samples sent to Parabon, including one
two-person mixture (not made known to Parabon, but Parabon readily detected the mixture and identified the contributors)
• Each sample genotyped on the Illumina CytoSNP-850K chip (851,274 SNPs) and run through the Snapshot algorithms
• Phenotype predictions compiled into a detailed report for each subject, including a predicted composite in which differences from the average face for the same sex and ancestry were
emphasized • Age and body mass index (BMI) values then delivered to
Parabon, and subjects with large differences from default age (25) and BMI (22) age-progressed by a forensic artist
• Photographs and self-reported ancestry and phenotypes collected by UNTHSC, and predictions for each Level 1
phenotype (sex, pigmentation, ancestry) compared to actual phenotypes
• Next phase will incorporate 3D scanning and craniofacial
measurements to assess accuracy of predicted face morphology
Study funded in part by the National Geographic Society
Blu
e
Haze
l
Bla
ck
VF
air
Fair
LtB
rn
Bro
wn
DkB
rn
Gre
en
Bro
wn
Blo
nd
B
row
n
Bla
ck
-Red
+
Red
Zero
F
ew
S
om
e
Many
Blu
e
Haze
l
Bla
ck
VFair
Fair
LtB
rn
DkB
rn
Gre
en
Blo
nd
Bla
ck
-Red
+
Red
Zero
F
ew
S
om
e
Many
Blu
e
Haze
l
Bla
ck
Bro
wn
Bro
wn
Bro
wn
VF
air
Fair
LtB
rn
DkB
rn
Gre
en
Blo
nd
Bla
ck
-Red
+
Red
Zero
F
ew
S
om
e
Many
Blu
e
Haze
l
Bla
ck
Bro
wn
Bro
wn
Bro
wn
VF
air
Fair
LtB
rn
DkB
rn
Gre
en
Blo
nd
Bla
ck
-Red
+
Red
Zero
Few
S
om
e
Many
Blu
e
Haze
l
Bla
ck
Bro
wn
Bro
wn
Bro
wn
* D
id n
ot
giv
e p
erm
issio
n t
o u
se im
ag
e
§ S
elf-r
ep
ort
ed
°
Blo
nd
as a
young
ad
ult