Obstructions to matching the missing and UID -Q&A's/FAQ's only please!

Discussion in 'Unidentified "How To" & Reference Forum' started by Cubby, Feb 13, 2011.

  1. Cubby

    Cubby fly the W!

    Messages:
    75,232
    Likes Received:
    131
    Trophy Points:
    63
    So what keeps us from matching the missing and unidentified - in addition to not being in a database?

    Let's please try and keep this a Q&A' thread only- close to a non discussion thread as we can, please.

    I'm hoping Carlk' will give us a laymans example of:

    Dentals:
    How do they mistakingly rule out?

    DNA:
    How does Mitochondrial versus Nuclear compare when it is available in Codis?

    -What if the missing person only has Nuclear available and no mitochondrial available? What obstacles will ME have?


    Any other FAQ's for uid's and the missing please add.

    thanks,

    Cubby
     
  2. Loading...

    Similar Threads - Obstructions matching missing
    1. kpdx
      Replies:
      0
      Views:
      1,374
    2. not_my_kids
      Replies:
      2
      Views:
      717

  3. CarlK90245

    CarlK90245 UID Moderator Staff Member Moderator

    Messages:
    7,935
    Likes Received:
    47
    Trophy Points:
    48
    I am cross-referencing my comment from another thread to here for general reference.

    I was pointing out as concisely as I could why it is that if they have only nuclear DNA on a missing person and only mitochondrial DNA on the UID (or vice versa), you still won't be able to make a valid comparison.

    The cases of Mindi Chambers and DoeNet Case 72UFTX are an example of two cases where authorities believe there is a match, but they cannot prove it because they only have mtDNA from the UID, and only nucDNA from paternal relatives. No maternal relatives are available to resolve this likely match.

    http://doenetwork.org/cases/72uftx.html
    http://www.charleyproject.org/cases/c/chambers_mindi.html

     
  4. Cubby

    Cubby fly the W!

    Messages:
    75,232
    Likes Received:
    131
    Trophy Points:
    63
    Thanks Carl, I did not mean to put you on the spot. I thought this might be a good area for FAQ's regarding obstacles such as DNA and dentals when it comes to official matches for the unidentfied. :blowkiss:

    TY!
     
  5. CarlK90245

    CarlK90245 UID Moderator Staff Member Moderator

    Messages:
    7,935
    Likes Received:
    47
    Trophy Points:
    48
    From a separate thread, addressed here to avoid going off-topic.

    I was told by Hal Brown (from the Delaware State MedEx Office) that Family Reference Samples (FRS) are processed entirely by an automated system, and any nucDNA samples taken from maternal relatives are also processed for mtDNA.

    However, if only paternal relatives are available (e.g., Mindi Chambers), no mtDNA profile can be developed.

    Also, if the unidentified body is too badly degraded, they might not be able to extract nucDNA even if they are able to extract mtDNA. As I understand it, mtDNA is more resistant to degradation than nucDNA.

    Also, although it is often denied that there are known instances of false negatives in CODIS, I know of one instance where DNA was available in CODIS for both the MP and the UID, and a hit was not triggered.

    Dawn Renee Higdon of Ridgecrest CA went missing in Aug'88 and her skeletal remains were found in Jul'90 in San Bernadino County.

    Here is the link to info regarding Dawn (no info is available about the previously unidentified remains)
    http://forthelost.wordpress.com/2010/08/02/dawn-higdon-missing-twenty-two-years/

    These cases remained unmatched despite the existence of a single FRS from one of Dawn's relatives, and a DNA profile for the UID in CODIS. (I'm not sure whether they were nucDNA or mtDNA, or whether the single relative was maternal or paternal). It was only after additional relatives submitted FRS samples that a feature in CODIS called "Pedigree Tree" evaluated the multiple samples collectively and then was able to flag the match to the UID case.
     
  6. CarlK90245

    CarlK90245 UID Moderator Staff Member Moderator

    Messages:
    7,935
    Likes Received:
    47
    Trophy Points:
    48
    Here is some additional info from David Van Norman in response to two questions that I posed to him. My questions were:

    (1) Is it a correct assumption that If only a mtDNA sample is available for a missing person, and only a nucDNA sample was available for the unidentified decedent, CODIS would not be able to identify the match?

    (2) If only one sample of familial nucDNA is available to compare to the nucDNA of the UID, is there a significant risk of a false negative?

    He responded as follows:
     
  7. Ms Suzanne

    Ms Suzanne Active Member

    Messages:
    6,554
    Likes Received:
    22
    Trophy Points:
    38
    I was just going to ask this same question.What if there is no DNA for the missing person.So her sister put in CODIS her DNA for a match with a Jane Doe and her missing sister.I believe they would have gotten mtDNA from the sister right?My question please is will the Unidentified Jane Doe with only nucDNA show up a match with the sisters mtDNA as a CODIS match?I hope I explained that right.I'm sorry.
     
  8. CarlK90245

    CarlK90245 UID Moderator Staff Member Moderator

    Messages:
    7,935
    Likes Received:
    47
    Trophy Points:
    48
    The standard practice is to get both nucDNA and mtDNA from the Family Reference Sample (FRS) submitted by the relative. However, with unidentified remains, both DNA types aren't always obtained. As VanNorman indicated above, different jurisdictions have different priorities.

    If the sister provides the only FRS for comparison, then a mtDNA comparison would be possible (assuming that she and the missing person have the same mother). However, according to VanNorman, CODIS requires more than one relative to submit DNA for the more definitive nucDNA comparison.

    However, a mtDNA hit only means that the two people compared are connected in the family tree by a continuous chain of female relatives. That connection may span over multiple generations, up one branch of the family tree and down another, and may involve distant relatives that the two people never knew.

    a nucDNA hit is more definitive, but you need more than one FRS to achieve statistically significant results.

    No. Mitochondrial DNA (mtDNA) is entirely different from Nuclear DNA (nucDNA). mtDNA comes from sub-microscopic organisms within our cells called mitochondria. A mitochondrion is not an inherent part of the person in which it resides, and therefore, it has a completely different DNA sequence from the nucDNA that uniquely defines each person.
     
  9. JeannieC

    JeannieC New Member

    Messages:
    4,996
    Likes Received:
    6
    Trophy Points:
    0
    I'm stumbling through this and it is all new to me so please excuse my ignorance.

    Are you saying that NucDNA comes from the father or the males in the family?
     
  10. CarlK90245

    CarlK90245 UID Moderator Staff Member Moderator

    Messages:
    7,935
    Likes Received:
    47
    Trophy Points:
    48
    No - nucDNA comes from both the father and the mother. Our nucDNA is an approximate 50-50 mix of the nucDNA from both parents.

    Mitochondria are also found in most of the cells of both males and females, including a female's egg cells. But they are virtually absent in a male's sperm cells. Consequently, mitochondria are passed to us only from our mothers, and the mtDNA taken from the mitochondria is not a 50-50 mix from both parents. It's a 100% duplicate of the mtDNA from the mother.

    I had said earlier that a mitochondrion is not an inherent part of the person in which it resides. To use an analogy, a mitochondrion is to the cell in which it resides, as a leech is to the whale on which it resides. A mitochondrion's DNA is different from the nuclear DNA of the host, just as a leech's nucDNA is different from the nucDNA of the whale.
     
  11. Ms Suzanne

    Ms Suzanne Active Member

    Messages:
    6,554
    Likes Received:
    22
    Trophy Points:
    38
    I have a question if someone knows the answer to.If you have an adult Unidentified male that has Partial (6) STR's and full mito profile recovered from remains and a little boy with only mito DNA on him.Can they find a relationship between them?I hope I said that right.
     
  12. Donjeta

    Donjeta Adji Desir, missing from Florida

    Messages:
    19,248
    Likes Received:
    4
    Trophy Points:
    38
    What kind of relationship? Do you mean if they're the same person? Since both have a mitochondrial DNA profile available they can be compared.

    If you're asking about a familial relationship they might be able to match the boy to adult males that he's maternally related to, that is, his brothers, sons of his maternal grandmother, but mitochondrial DNA can't be used to determine the adult male is the boy's father, for example.
     
  13. CarlK90245

    CarlK90245 UID Moderator Staff Member Moderator

    Messages:
    7,935
    Likes Received:
    47
    Trophy Points:
    48
    It depends on what their actual relationship is to each other. If they are brothers with a common mother, the mtDNA comparison will result positive. But it won't prove what their relationship is to each other. It only shows that they are linked by one or more female ancestors along the maternal line of their family trees. That common female ancestor could be a mother, maternal grandmother, or several generations above that.

    If the relationship is father/son, the mtDNA test will result negative.

    The partial STR is irrelevant in your hypothetical because they don't have nucDNA on the boy. Assuming that they had nucDNA on the boy, they could do a manual comparison, but CODIS requires a full 13 alleles in the STR profile, so they wouldn't be able to put the UID male in CODIS.
     
  14. Ms Suzanne

    Ms Suzanne Active Member

    Messages:
    6,554
    Likes Received:
    22
    Trophy Points:
    38
    Thank you.I was thinking Father and son.
     
  15. believe09

    believe09 Active Member

    Messages:
    28,114
    Likes Received:
    22
    Trophy Points:
    38
    One additional point, Ms Suzanne-IIRC Paternal/Y DNA mutates one in about 500. So it is possible for a boy to be related to a man, but the paternal DNA might indicate otherwise. Paternal DNA needs to be, usually, corroborated by a family history.

    http://dna.ancestry.com/learnMorePaternal.aspx
     
  16. kpdx

    kpdx Jane Doe was discovered Aug. 14, 1977 outside of E

    Messages:
    454
    Likes Received:
    0
    Trophy Points:
    0
    Thanks so much for this, CarlK, it was a very elegant, concise demystification of an otherwise complicated issue.

    In the case of Mindi, who looks to be an obvious match, can they not compare dentals..especially since Mindi would of at a min. had records from orthodontist?

    Another question that comes up consistently (and has resulted in rule outs) is height. Typically, UID's have a range provided (as in the case of the TX Jane) whereas MP have an exact number. I'll address this to the broader forum as I know we have lots of experts around :)

    1st Q: As I understand it, height is based on comparing measurements of specific bones with established height chart. Is this standard practice, or does it vary based on decomp? What is the general practice of ME when determining height?

    2nd Q: A recent doctor visit identified that my own medical records had me at a shorter height than I am (in my 30s, so obviously not a result of a growth spurt). I always assume a margin of error in a MP's height...but how does LE treat it? Are heights self reported by family, or are they based on medical records? Are medical records accessible to LE when investigating MP? Over the years, I have seen rule outs based on a difference of a few inches when otherwise the match looks good....

    Thanks!
     
  17. CarlK90245

    CarlK90245 UID Moderator Staff Member Moderator

    Messages:
    7,935
    Likes Received:
    47
    Trophy Points:
    48
    Either they were unable to obtain records from Mindi's orthodontist, or they were unable to locate the orthodontist at all.

    Normally, with skeletal remains, they compare the length of the femur (or other available long bone) to a height chart. The standard heights would also depend on the gender and race of the person.

    I suppose LE uses whatever is available. It could be medical records, or a driver's license, or if nothing else is available, an estimate provided by family.

    I hate to see rule-outs based on height, because I've seen many instances where after a person is identified, the UID height differed from the MP's listed height.
     
  18. Donjeta

    Donjeta Adji Desir, missing from Florida

    Messages:
    19,248
    Likes Received:
    4
    Trophy Points:
    38
    How does Namus determine if the strength of the profile or the probability for an ID is high or low? Do they only see if there are dentals, DNA and fingerprints on file?

    For example, this case is marked low probability
    https://identifyus.org/cases/9656 although it seems like a no-brainer because they found a driver's license with a name on it and there is a matching person missing in the area.
    http://www.charleyproject.org/cases/e/eakin_daniel.html

    They only found partial remains so there is not much identifying info in the bones themselves.
     
  19. deca

    deca New Member

    Messages:
    2,229
    Likes Received:
    1
    Trophy Points:
    0
    I was looking on NamUs and an UID was listed with almost no information. It just had race, date found and where found. No height, weight, age guess- nothing. Does that happen often, or is it a mistake? What do you do about this?
    I was trying to match a missing person up and I felt like a hit a brick wall. Newbie here so I am hoping this question is in the right place.
     
  20. deca

    deca New Member

    Messages:
    2,229
    Likes Received:
    1
    Trophy Points:
    0
    Correction- there was an age estimate- but hard to figure out anything when there is no height/weight, how old bones were etc.
     
  21. CarlK90245

    CarlK90245 UID Moderator Staff Member Moderator

    Messages:
    7,935
    Likes Received:
    47
    Trophy Points:
    48
    I was watching the National Geographic channel last night, and they were doing a story about the famous National Geographic magazine cover photo of the Afghan Girl with the amazing green eyes, taken at a refugee camp in 1984. For years, the photographer who took that photo had wondered what became of the girl and went great lengths trying to find out what ever became of her. After showing the photo to people all over Pakistan and Afghanistan and encountering numerous false leads, he finally located her, married with children and living in Pakistan.

    To verify that they had located the same woman, they sent her photo to facial recognition experts at the FBI and the NCMEC, and by analyzing the detail in their irises, they verified with over a million-to-one probability that it was the same woman, despite the fact that her eyes seem to have darkened somewhat with age.

    [​IMG]

    In ruling out one of the false leads, the FBI facial recognition expert mentioned something that I thought to be relevant to our efforts. He said that 99% of the time, a small mole on someone's face will not disappear. It will remain there for life, or grow larger.

    He had originally pointed out a spot on the right side (her right, not ours) of the girl's upper lip, and didn't see a corresponding spot on her older photo. But after looking at other photos taken of the girl at the same time, it turned out to be just a spot of dirt on her face. But you can see other spots on her forehead and below the right corner of her mouth in the "then" photo that match up on her "now" photo.

    So we should keep this in mind when when comparing MP photos to UID postmortem photos. If you see even a tiny mole on the face of the MP that doesn't appear on the UID, you can be reasonably certain that it is a non-match. But you should be certain that it truly is a facial blemish, and not just a speck of dirt.
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice