Immigration other newsletters
October 30, 1998
Immigration is a sub-menu option of Paternity case, and it is an alternative to Calculate report. It becomes available after a case has been defined, and data has been created for the people in the case. Then, Select case, and choose Immigration. A window opens wherein you can type in the kinship formula (i.e. the specification of pedigrees). For a standard paternity trio analysis, you would type
C : M + F/?
The standard "role" letters -- M, F, C, D, etc -- are used to name people.
You don't type in the genotypes; the program will add the genotype specifications iteratively, locus-by-locus, as it makes the calculation across all loci for which there is data.
The Immigration feature is so named because one typical use is analysis of claims of relationship that potential immigrants make to bolster their applicant status, and because I am not very inventive at creating names. However, it is of course also useful for every kinship situation, including inheritance, missing persons, etc.
This feature is experimental, in development starting with version
21.03 of DNA·VIEW.
SwissAir crash victims
Last month I was privileged to be invited by Dr. Fourney of the RCMP
to help sort out DNA identifications of the SwissAir flight 111 crash
victims. The questions to be answered were of the form: Given a set
of related-looking DNA types from the crash (possibly a family that
perished), and given a collection of living relatives as plausible
referents, how certain can be we as to the identities of the various
victims? Since there was typically little in the way of physical
clues from the crash samples, many different combinations could
potentially be considered; a large number of kinship scenarios needed
to be calculated.
The project proved to be an excellent test of the new program. Since each configuration that I wished to test could be evaluated in only a minute or so, it was feasible to test a large number of possibilities -- although not possible to compare individually every possibility. However, I eventually came to understand a way to arrange all the conceivable relationships among the people in a hierarchical fashion, using a type of arrangement called a "lattice." The lattice represents a set of assumptions about which permutations of individuals are more plausible than others. At most a few comparisons are necessary to confirm that the lattice's structure is correct, and to compare the best explanation for the DNA evidence with a handful of possible second-best explanations. The smallest likelihood ratio among this handful -- usually it was over 1 million -- represents the superiority of the best explanation over any other explanation, a conclusion that is established confidently without requiring the tedium of examining most of the possible explanations.
Also posted are validation/accreditation studies from the Amsterdam Red Cross lab.
T E S T OBSERVED PHENOTYPES CALCULATION OF PATERNITY INDEX Tested Paternity Nonpaternity Ratio Mother Child Man Assumed (X) Assumed (Y) (X/Y) PCR alleles FGA/4q 5,6 6,5 0.5 0.00256 195 TH01/11p15.5 8,10 9,10 9 0.5 0.0871 5.74 DNA Probes (Kbase) TBQ7/D10S28 1.94 1.12 1.12 0.25 0.0378 6.62 Hae III 1.12 1.94 1.55 D17S26/EFD52 4.28 5.21 5.21 0.25 0.0192 13 Hae III 7.03 7.03 2.55