Author Topic: Thoughts on the case. Setting up familial DNA databases  (Read 3179 times)

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Offline Miss Taken Identity

Re: Thoughts on the case. Setting up familial DNA databases
« Reply #210 on: January 06, 2019, 10:40:55 PM »
Did familial DNA testing come up in the McCann case?  https://www.mccannpjfiles.co.uk/PJ/JOHN_LOWE.htm 

Big section of the report is discussing whether the DNA samples came from a relative of Madeleine.  I need to read it again now that I have started to understand Familial testing.

"Basic information on the establishment of DNA profiles.

DNA is a complex chemical that is found in the majority of cells in the human body, including cells in the blood, semen, saliva and hair roots. DNA carries genetic information that determines physical characteristics of a person and directs the processes involved in the functioning of an organism. This information exists in the form of a code, half of which is inherited from the father and [half] from the mother.

Except for truly identical twins, the DNA of each person is unique, although the technology currently available today does not permit the analysis of all the differences between persons. The techniques used by FSS analyses specific regions of DNA known as short tandem repeats (STRs), that are known to be amply variable from individual to individual. The techniques of establishing DNA profiles can, therefore, be used to exclude, conclusively, one person as the donor of an unknown DNA source, and can, frequently, provide convincing indications in terms of participation [contribution - ], though not allowing, as yet, proof of identity.

The establishment of DNA profiles (STR) uses the technique of DNA amplification, through which specific DNA regions are selected and copied many times. This increases the quantity of DNA available for analysis and means that a DNA profile can be obtained from samples in which the initial quantity or quality of DNA is not adequate for other methods of establishing profiles.

In this way, DNA profiles are produced through amplification (copying) of eleven different areas of DNA. Ten of those areas contain STR. They are known as D3, VWA, D16, D2, D8, D21, D18, D19, THO1 and FGA. The eleventh, known as amelogenina, indicates the sex of the donor. The individual components of a DNA profile are represented by a series of peaks that can be measured, allowing them to be attributed a designation [labelled - ]. One person will have two peaks in each STR, one inherited from each progenitor [parent], unless the same STR has been inherited from both progenitors, in which case only one peak will be observed.

If the DNA profiles relating to a stain, obtained from a crime [scene], and [that of] a suspect reveal no differences, it is said that they match. The estimation of the amount of the level of proof of DNA profiles that match between, for example, a stain of body fluid and a suspect, consists of calculating the probability of obtaining the match if, in reality, the stain was not from the suspect, but was from another individual with the same DNA profile. That is known as the probability of correspondence [matching].

The probability of matching depends upon the level of kinship [parental similarity] existing between the suspect and another individual. True identical twins have the same profile. But, due to the random manner in which DNA from the two progenitors combine to form the descendant, the probability of two siblings presenting a match in all ten STR regions is, approximately, one in ten thousand (1 in 10,000). The more distant the relationship becomes between two persons, the more reduced becomes the probability of matching in all ten STR regions.

For example, the probability of two first cousins having the same profile is of the order of one to one hundred million (1 to 100-million).

Where there exists no clear indication that a relative close to the suspect is involved, it is common practice to indicate a probability of matching relative to an unknown person who has no kinship with the suspect. With a complete profile this probability of matching is of the order of one to one thousand million (1 to 1,000-million) [or 1 to 1-billion using U.S. numbering].

In the case of a partial profile being obtained, the probability of matching is calculated using reference databases [tables] that contain calculated proportions of each DNA profile component present in the general population. These estimates are then combined in a manner that permits compensation for possible associations between DNA components in order to establish the calculation of the probability of matching relating to the partial DNA profile.

The calculations of probability of matching are done using three databases containing DNA profiles obtained previously from individuals of caucasian, afro-caribbean and asiatic descent of this country [namely, U.K.] When the racial origin of a person who left the biological material is not known, the result presented in the deposition will be the lowest of the results obtained."

based on this part of the file:

 "In my opinion, the results detailed above provide extremely strong support for the view that the profile obtained from the pillowcase originates from a natural child of Kate HEALY and Gerald McCANN.

Please note: I understand that the McCANN - s have a second female child. It therefore remains a formal possibility that the DNA on the pillowcase could have originated from her as the genetics would be in keeping with those described above."

There was DNA samples provided. However, the results were not unexpected to be fair. It was established both Kte and Gerry were her parents BUT it also mentions ,quite interestingly, another female child - which if was left on the bed would show up the same results.

What the results didn't do was to state without predjudice that someone elses DNA was on that bed i.e  the 'abductors' Nlow let us look at this or even do a trial at home. lay a child or doll on the bed as if it was sleeping and try tpo lift it without touching or brushing the bed at all...

On top of this there are no hand prints,  glove fibers,  foot prints, scuff marks... nothing!
'Never underestimate the power of stupid people'... George Carlin

Offline Robittybob1

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Re: Thoughts on the case. Setting up familial DNA databases
« Reply #211 on: January 06, 2019, 11:21:48 PM »
based on this part of the file:

 "In my opinion, the results detailed above provide extremely strong support for the view that the profile obtained from the pillowcase originates from a natural child of Kate HEALY and Gerald McCANN.

Please note: I understand that the McCANN - s have a second female child. It therefore remains a formal possibility that the DNA on the pillowcase could have originated from her as the genetics would be in keeping with those described above."

There was DNA samples provided. However, the results were not unexpected to be fair. It was established both Kte and Gerry were her parents BUT it also mentions ,quite interestingly, another female child - which if was left on the bed would show up the same results.

What the results didn't do was to state without predjudice that someone elses DNA was on that bed i.e  the 'abductors' Nlow let us look at this or even do a trial at home. lay a child or doll on the bed as if it was sleeping and try tpo lift it without touching or brushing the bed at all...

On top of this there are no hand prints,  glove fibers,  foot prints, scuff marks... nothing!
That "other female child" - are you talking about Amelie?
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Offline Robittybob1

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Re: Thoughts on the case. Setting up familial DNA databases
« Reply #212 on: January 06, 2019, 11:45:45 PM »
If a person commits a crime and gets caught and they have to submit a sample to the offenders DNA base, I'm wondering if it would be possible to get the perpetrator's parent's DNA profile as well.

If you know the parent's DNA it would be able (I'm thinking) to identify biological siblings of the offender.
Even if the sibling was the extreme and had no alleles the same as the offender at all loci they would still have one allele same as the mother and one to the father.  If that ever happened I'd say the odds of that person not being a full sibling would be extremely small.
If that person was a half brother or half sister they would still have at least one of the alleles at each site over all of the loci the same as one of the parents.

I'm having a feeling that is a big ask as often the parents are already deceased.  Maybe it will take another half century to really become viable if they were to start collecting DNA profiles from all deceased persons.
« Last Edit: January 07, 2019, 06:41:54 AM by Robittybob1 »
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Offline Robittybob1

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Re: Thoughts on the case. Setting up familial DNA databases
« Reply #213 on: January 07, 2019, 06:45:42 AM »
I tend to think most jurisdictions keep at least 2 databases in operation:

"Familial DNA analysis consists of a deliberate search of Arizona Convicted
Offender and Arrestee DNA profiles to identify candidates who are potential
close biological relatives to an unknown perpetrator.

http://www.azdps.gov/sites/default/files/media/Familial%20DNA%20Analysis%20Flyer.pdf

1.  Convicted Offender and
2.  Arrestee DNA profiles

Maybe in the UK they lump them all into the one register.  I can't say the UK system is wrong for they get the best results AFAIK.


"With nearly 200,000 DNA profiles in the national databank, the pool of genetic information available to police is large, and growing – about 13,500 are added each year. A further 12,800 unidentified profiles from crime scenes are held in a separate databank, awaiting a match to an offender."
https://www.noted.co.nz/currently/social-issues/dna-criminal-investigations-violate-human-rights/
« Last Edit: January 07, 2019, 10:20:58 AM by Robittybob1 »
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Offline Robittybob1

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Re: Thoughts on the case. Setting up familial DNA databases
« Reply #214 on: January 07, 2019, 09:49:09 AM »
One of the more interesting stories on DNA analysis
"How police used DNA to solve some of NZ's high-profile criminal cases"
https://www.noted.co.nz/currently/crime/police-used-dna-to-solve-high-profile-criminal-cases/
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Offline Robittybob1

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Re: Thoughts on the case. Setting up familial DNA databases
« Reply #215 on: January 07, 2019, 10:58:08 PM »
In this case a crime was attributed to a person long deceased, but they were able to compare his DNA to a living relative who was on the offenders database. 
The murdered woman's sons who were elderly themselves by this stage felt a degree of closure knowing who it was who killed their mother. 
"Murder of 'Righteous Brothers' Singer's Ex-Wife Karen Klaas Solved 40 Years Later"
https://www.nbcnews.com/news/us-news/murder-righteous-brothers-singer-s-ex-wife-karen-klaas-solved-n714716
« Last Edit: January 10, 2019, 06:39:04 AM by Robittybob1 »
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Offline Robittybob1

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Re: Thoughts on the case. Setting up familial DNA databases
« Reply #216 on: January 09, 2019, 06:31:59 AM »
Unless this was to be an all inclusive international effort, I can foresee problems when crimes are committed by an immigrant whose family group remain back in the 'old country', so that familial matches may never be found.
Could that be a condition of residency - the immigrant parents need to submit to a DNA profile.
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Offline Carana

Re: Thoughts on the case. Setting up familial DNA databases
« Reply #217 on: January 13, 2019, 07:03:01 AM »
From the above link:
"Current forms of familial DNA searches work only with men. This is because techniques in common use to determine exact familial relations involve analysis of similarities on the Y chromosome."

There could be ways around this.

I don't see why they don't use mtDNA analysis as well. Mystery.

Offline Robittybob1

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Re: Thoughts on the case. Setting up familial DNA databases
« Reply #218 on: January 15, 2019, 10:08:58 PM »
I did receive a reply from Alexander Flaus:

".... Thanks for taking the time to email me.

 

I think your proposal is really interesting and provides a different solution to address some of the issues in this area, while still allowing the benefits of this technology to be utilised. One thought is that this seems like it could be a really good way to increase the pool of DNA profiles available, and the diversity of those profiles. However, it could be a very hard thing to sell to the public from a privacy perspective, though people are becoming more and more tolerant of forfeiting privacy when needed.

 

Unfortunately Iím not as up to date on the issues in this area as I was at the time I wrote my thesis. My partner just read a book that he really enjoyed (that youíve no doubt read) which addresses the use of familial DNA searching Ė Iíll be Gone in the Dark by Michelle McNamara. Iím yet to read it, but understand that the Golden State killer was caught through the use of publicly available DNA information on ancestry websites.  Another interesting angle to consider.

 

My view has always been that Familial DNA is a really powerful tool to use but that we need to have appropriate legislation or regulations in place and to have had conversations about where we want to go with this technology.  Because science moves so quickly, the law tends to lag behind meaning new technologies are often used before weíve had a chance to consider how we think they should be used.

 

I hadnít realised that ESR only keeps results on file for 10 years on average, agree that limits the potential uses of familial DNA testing. Assume that decision has been made for privacy reasons where individuals havenít committed any crimes for an extended period of time?

 

Again, thanks very much for your email. Great that youíve gotten interested in this area, lots of new technologies out there that could be used to solve criminal cases and great if people are having discussions about how best these can be used. 
...."

I'm not sure what to do now. 
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Offline Eleanor

Re: Thoughts on the case. Setting up familial DNA databases
« Reply #219 on: January 16, 2019, 01:36:41 AM »

Do you have an MP, Rob?  I don't know much about The New Zealand Parliament.

Offline Robittybob1

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Re: Thoughts on the case. Setting up familial DNA databases
« Reply #220 on: January 16, 2019, 06:41:14 AM »
Do you have an MP, Rob?  I don't know much about The New Zealand Parliament.
Yes I do, Nathan Guy who owes me a favour actually.
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Offline Eleanor

Re: Thoughts on the case. Setting up familial DNA databases
« Reply #221 on: January 16, 2019, 08:01:37 AM »
Yes I do, Nathan Guy who owes me a favour actually.

Have you tried him?

Offline Robittybob1

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Re: Thoughts on the case. Setting up familial DNA databases
« Reply #222 on: January 16, 2019, 11:22:09 AM »
Have you tried him?
You've got me thinking. 
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