familias
a program for paternity and identification cases
The familias
program may be used to compute probabilities and likelihoods in cases
where DNA profiles of some people are known, but their family
relationship is in doubt. The program extends the previous program
known as pater,
in that multiple alternative pedigrees can now be handled. Given
several alternative family trees (or pedigrees) for a group of people,
given DNA measurements from some of these people, and given a data base
of DNA observations in the relevant population, the program may compute
which pedigree is most likely, and how much more likely it is than
others. Obviously, there are several other programs performing similar
tasks. As far we know a distinguishing feature of familias
is its ability to handle complex cases where potential mutations are
accounted for, together with its ability to handle multiple pedigrees
simultaneously. Background
The familias program (and previously the pater program) has been developed by Petter Mostad and Thore Egeland at the Norwegian Computing Center, in cooperation with Bjørnar Olaisen, Margurethe Stenersen, and Bente Mevåg at the Institute of Forensic Medicine
(RMI) in Oslo. The Norwegian Computing Center is a non-profit institute
for applied research. The cooperation with RMI started in 1994, and the
program was made in 1995. Since then, a number of Forensic laboratories
have bought the program, and there have been several ideas for
extensions and improvements. The program is now released as freeware.
The last revision, version 1.7, was released in February 2005. Method
The simplest cases in which the familias
program can be used are paternity cases, i.e., cases where one wants to
determine whether a man is the father of a certain child. In general,
one would have DNA data for the child, the mother, and the putative
father. One would also need data bases with the frequencies for the
observed alleles in the relevant population. Given this, the program
will calculate the odds for the putative father being the real father. In
such paternity cases, one may say there are two alternative hypotheses,
i.e., two alternative pedigrees: One where the man is the father, and
one where he isn't. The strength of familias
is that it may calculate odds for any pair of alternative pedigrees.
Thus, it may be used to calculate whether an uncle is indeed an uncle,
whether two girls are indeed sisters, and so on. In fact, multiple
different hypotheses may be handled. In
some systems used for human DNA typing, mutations are fairly frequent.
If the possibility of mutations is not considered, one may mistakenly
exclude a pedigree that turn out to be the correct one after
considering all the data. The familias program has the ability to weigh the possibility of mutations against other evidence. Code
Version 1.81 of the code is now available. It has been tested with Windows XP. To install, download familias.zip
(2.2MB), extract the three files Familias.CAB, setup.exe and SETUP.LST,
and doubleclick on setup.exe. NOTE: Some problems with running version
1.81 under Windows 2000 have been reported, we will look into this
soon. The previous version, 1.7, is available here. A short summary of the difference between versions 1.6 and 1.7 is given here (will be updated soon). The installed program should respond with "This is familias, version 1,81" when you select Help->About.
If you do not get this reply, try to remove any previous versions of
familias before reinstalling it. In addition to removing the program,
it may be necessary to manually locate and remove the file
V10familias.dll prior to reinstallation on computers with older
versions of Windows. Manual
The manual is available here, in pdf-format. A short tutorial is available from the help-menu of the program, but can also be seen here. Examples
Exercises with some solutions are available here. The example files referred to are available below: Note that files created by familias are best viewed with Microsoft WordPad and NOT Microsoft Notepad. In addition to the files above, some example files with allele data and case data in the format that can now be read by familias are available. Registration
If you download and start to use familias, we ask you to send us a mail, where you include Citing Familias
Egeland, Thore; Mostad, Petter; Mevåg, Bente; Stenersen, Margurethe: "Beyond traditional paternity and identification cases. Selecting the most probable pedigree." Forensic Science International Vol 110, Nr. 1, 2000. Some other references
Egeland, Thore; Mostad, Petter: "Statistical Genetics and Genetical Statistics: a Forensic Perspective". Scand. Journal of Statistics, Vol 29, 2002. Olaisen,B, Stenersen, M and Mevåg, B: "Identification by DNA analysis of the victims of the August 1996 Spitsbergen civil aircraft disaster", Nature Genetics Vol. 15, April 1997(402-405). J. Drábek: Validation of software for calculating the likelihood ratio for parentage and kinship Forensic Science International: Genetics, Volume 3, Issue 2, Pages 112-118. (2008)
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