Here's what the FBI has for DNA (released Sept. 29, 2009). DNA gathered for the purposes of matching it to items found having to do with the crime scene by graphing STR (short tandom repeats or genetic variants).
CA(K5-1)
15,16 / 15,18 / 20,21 / X / 13,14 / 30,32 / 14,16 / 11,14 / 9,14 / 10,11
GA(K7-1)
15,19 / 18,19 / 22,25 /XY/ - 14 - /- 30 - / 14,17 / 12,13 / 11,12 / - 12 -
LA(K9-1)
15,19 / 17,19 / 20,25 /XY/ - 14 -/- 30 - / 14,17 / 11,12 / 12,14 / 11,12
KC(K1-1)
15,19 / - 18- / 20,25 / X / 13,14 / -30 - / 14,17 / 11,12 / 11,14 / 11,12
Caylee(Q18-1)
14,15 / 17,18 /20,24 / X / 12,13 / 28,30 / 14,16 / 11,12/ 11,12 / 11
*(19)---------------------(14)*
You inherit one number each from each parent. If there is one number, then you got that number from both parents. "At each locus a person has two alleles one from each parent. When there is only one allele, by chance the person inherited the same allele from each parent."
*appears like that on the FBI report
This is how they could tell that the toothbrushes had a mixture of DNA on them. By the way, how common is it for family members to use the same toothbrush? We don't at our house.
Parentage Report from August 15, 2005
Casey
13,14 / - 30 - / 11,12 / 10,11 / 15,19 / 6,8 / 11,14 / 9,12 / 17,24 / 13,14 / -18 - / 8,11 / 14,17 / 11,12 / 20,25
Caylee
12,19 / 28,30 / - 11 - / - 10 - / 14,15 / 8,7 / 11,12 / 9,13 / -17 - / 13,15 / 17,18 / - 8 - / 14,16 / 11,12 / 20,24
The report from 2005 (Jesse's) is more detailed as it contains more allele.
Each set of numbers (or number) corresponds to another number (ie, D75820 or D21511 that means something ) and a lab can measure the odds of different combinations of people who could produce these combinations and arrive at a percentage of possiblty for another set of DNA to produce the outcome of the child's DNA.
"phenotypes for H and I similarities at highly heterozy-gous DNA loci is useful in suggesting incest."
"in some cases incest detection may arise during a regular paternity test."
Mitochondria DNA from a mother's cells can be used to tell how old the father is if when you know the age of the child.
This completes my study thus far.
I also learned 'if you determine the obligate allele in the child then you can determine if the man also carries this allele.' What is the obligate allele?
Keep in mind that KC would not consent to a DNA test. OC had to serve a search warrant.
Allele numbers can moderate for different reasons (see the number 17 in Lee's DNA that is not seen in either CA's or GA's). I was not able to find an explanation of how an incest victim's DNA might vary from 'regular' couples' DNA other than there is an increased incidence of undersirable recessive genes.
Also keep in mind, some of the information above, may not be explained 100 percent accurately because I'm interpreting what I'm learning based on a self imposed crash course.