Forensic DNA database

Question 1

What is CODIS?

Answer 1

Combined DNA Index System

CODIS is the FBI’s program of support for criminal justice DNA databases as well as the software used to run these databases.

Question 2

How many core loci underly CODIS and how many population datasets are included?

Answer 2

13 core loci

over 50 population databases; more than 10 000 individuals

Question 3

What does YHRD stand for?

Answer 3

Y-STR Haplotype Reference Database

Question 4

How many core loci are defined by SWGDAM for Y-STR analysis?

Answer 4

11

Question 5

SWGDAM recommendations for mtDNA typing

Answer 5

• GLP and follow specific protocols
• Negative and positive controls and extraction reagent blanks
• reported sequences must be based on redundant information from forward and reverse primers
• manual transcription should be avoided
• independent confirmation by two scientists
• labs shall participate in proficiency testing programs
• sequence entire mitochondrial DNA control region in population genetic studies
• report relative to rCRS, allignment needed
• use IUPAC convention
• use analytical software that checks for phylogenetics
• be able to justify choice of database and statistical approach
• establish statistical guidelines for reporting match between two samples

Question 6

SWGDAM recommendations for mtDNA heteroplasmy

Answer 6

• labs have to establish their own guidelines on how do deal with them
• “differences in both PHP and LHP do not constitute evidence for excluding two otherwise identical haplotypes as deriving from the same source or same maternal lineage”
• put the dominant variant into database