Mitochondrial DNA error prophylaxis: assessing the causes of errors in the GEP'02-03 proficiency testing trial.
We report the results of the Spanish and Portuguese working group (GEP) of the International Society for Forensic Genetics (ISFG) Collaborative Exercise 2002-2003 on mitochondrial DNA (mtDNA) analysis. Six different samples were submitted to the participating laboratories: four blood stains (M1-M2-M3-M4), one mixture blood sample (M5), and two hair shaft fragments (M6). Most of the labs reported consensus results for the blood stains, slightly improving the results of previous collaborative exercises. Although hair shaft analysis is still carried out by a small number of laboratories, this analysis yielded a high rate of success. On the contrary, the analysis of the mixture blood stain (M5) yielded a lower rate of success; in spite of this, the whole results on M5 typing demonstrated the suitability of mtDNA analysis in mixture samples. We have found that edition errors are among the most common mistakes reported by the different labs. In addition, we have detected contamination events as well as other minor problems, i.e. lack of standarization in nomenclature for punctual and length heteroplasmies, and indels. In the present edition of the GEP-ISFG exercise we have paid special attention to the visual phylogenetic inspection for detecting common sequencing errors.
Salas
Antonio
A
Unidad de Genética, Facultad de Medicina de la Universidad de Santiago de Compostela, Instituto de Medicina Legal, A Coruña, Galicia-Spain. apimlase@usc.es
Prieto
Lourdes
L
Montesino
Marta
M
Albarrán
Cristina
C
Arroyo
Eduardo
E
Paredes-Herrera
Miguel R
MR
Di Lonardo
Ana Ma
AM
Doutremepuich
Christian
C
Fernández-Fernández
Isabel
I
de la Vega
Alberto González
AG
Alves
Cíntia
C
López
Carlos M
CM
López-Soto
Manolo
M
Lorente
José A
JA
Picornell
Antònia
A
Espinheira
Rosa M
RM
Hernández
Alexis
A
Palacio
Ana Ma
AM
Espinoza
Marta
M
Yunis
Juan J
JJ
Pérez-Lezaun
Anna
A
Pestano
José J
JJ
Carril
Juan Carlos
JC
Corach
Daniel
D
Vide
Ma Conceiçao
MC
Alvarez-Iglesias
V
V
Pinheiro
M F
MF
Whittle
Martín R
MR
Brehm
Antonio
A
Gómez
Josefina
J
D001801:Blood Stains; D019411:Clinical Laboratory Techniques / Q000592:standards*; D016172:DNA Fingerprinting / Q000592:standards*; D004272:DNA, Mitochondrial / Q000032:analysis*; D005260:Female; D006197:Hair / Q000378:metabolism; D006801:Humans; D008297:Male; D010334:Paternity; D010802:Phylogeny; D011786:Quality Control; D017422:Sequence Analysis, DNA / Q000592:standards
D004272:DNA, Mitochondrial