My sister and I have a perplexing situation. She believed a family friend to be a half brother, so they got a test at Biogene DNA. It states:
Based on the results of the analysis obtained from the DNA loci listed, the probability of Half-Siblingship is 94.3110% (in other words, 16.6 times more likely to be Half Siblings than Not Related). This probability is calculated by comparing to an untested, unrelated, random individual of the Other population (assumes prior probability equals 0.50).
My understanding is that this considered conclusive.
However, my mother, my sister, the friend and myself all did MyHeritage DNA tests and in the DNA comparison tools my sister and mother come up as matches. In fact my sister comes up as a full-sibling not a half-sibling. So this means either my sister and the friend are not half-siblings or my biological father is the same as the friend.
I have also downloaded the raw data from MyHeritage and uploaded it to GEDmatch. I'm able to get the expected matches for my mother and my sister. If I use the default settings for the one-to-one match it finds no matching dna for the friend and me or the friend and my sister. If I reduce the Minimum segment cM size to 1, I do get some matching with the friend.
Can anybody help me figure out if A) the Biogene test is wrong, or if B) I'm not using GEDmatch or MyHeritage correctly?