Ancestry DNA shock result

[rageagainstthemachine72]

My daughter did a dna test, results came back 25% Italian. I thought that's weird, that must mean one of her parents is half italian, so I did a test, yes you guessed it I'm 48% Italian and my two sisters who tested years ago came up as half sisters. Devastated, mum died two years ago and the man who I thought was my father died over 30 years ago. Not really sure what I'm looking for regarding this post, just some support and anyone out there with similar stories.

A previous poster has already replied to you about why you are wrong on both counts, but I would just like to expand on

"...how can you possibly find out you have half siblings or that your dad isn't your dad through this?"

It is done through a process called "autosomal DNA testing".

An autosomal DNA test measures your autosomal chromosomes, which make up the majority of your DNA. You inherit these chromosomes equally from both of your biological parents.

DNA comes in long stretches called chromosomes. Humans typically have 23 pairs of chromosomes for a total of 46. There are two broad categories of chromosomes, autosomal and sex chromosomes.

• Autosomal chromosomes, 22 matching pairs, make up the bulk of your DNA. Almost everyone has a complete set of them. An autosomal DNA test looks at the DNA from these 22 chromosome pairs.

• Sex chromosomes are made up of X and Y chromosomes, which differ in size and function. People usually have either a pair of X chromosomes or X and Y chromosomes.

Companies like Ancestry will look at around 700,000 DNA markers across all 22 pairs of chromosomes.

They will then look for large areas of shared DNA (where the DNA markers are the same in both people) between you and other people in their database. The greater amount of DNA shared between you and another person, measured in units of centimorgans (cM), the more closely you are related.

"...how can you possibly find out you have half siblings or that your dad isn't your dad through this?"

If your dad is your dad then he will typically share around 3,500 cM of DNA with you. If he is not your dad then you will not share any DNA at all.

However, if you don't have the father's DNA then it's slightly more complicated with half-siblings as there can be an overlap between the typical values found for a full-sibling and a half-sibling. Unless the amount of DNA shared is particularly low or particularly high then it could be either.

So, if the amount of DNA shared is between 1,600 cM and 2,400 cM then the other person could be either a half or full sibling.

You would then need to look at more distant relationships.

If both of the siblings are related to other people on the father's side of the family (I'm assuming here that they have the same mother) then that would indicate that they are full siblings.

If one sibling is related to other people on the father's side of the family but the other sibling is not, then that would indicate that they are half-siblings.

OP this is a shock and there is no right way to feel. My family is full of adoption and grandparents bringing up grandchildren as children and absent fathers replaced quietly by other men. Lots only came out years later. Personally while I have no dna match to my dad - quite obvious if you put us side by side - he is t the man who raised me, he is still my dad. My half sister I did t meet until we were both adults and he is actually now a sister but had we not got on could have stayed a stranger - there are other people on her side I don’t see. Basically those who brought me up - so my dna does t make me not theirs - love and familiarity makes family. For the half relations I found later - that only remained friends if they were people I would have liked anyway and I was blessed to get a sister from it. I will never know my birth dad - no big matches on that side and that is ok. I am absolutely me it have had much longer to be at peace with it all. Don’t let the shock take anything away from your feelings and love for your brother and sisters then in the longer term try and let any future matches can bring you extra but recognise it’s all drama and excitement at first but can burn out quickly like any overly intense relationship.

I am wondering what you think the dna used by the police to secure convictions is testing? It’s an amazing and complex subject.

Also you clearly don’t understand how recessive genes work. For example blue eyes are recessive and need two blue eye genes to pair and create . Each parent passes one gene down. Brown eyes are dominant so the passing down can be Br / /Br - brown eyes Br/bl - brown eyes bl/Br - brown eyes bl/bl - blue eyes so two brown eyed parents Br/bl bl/Br can absolutely have a blue eyed child.

Likewise the red hair gene is recessive so two brown-haired parents could both pass down a recessive red hair gene, and their child would have red hair.

Are you really this ill-informed, or are you just stirring the pot? 5-minutes with google would explain how this works.

The tests are fine. I used to fantasise that my parents weren't my parents.

they’re Either thick or a tee roll or both

Sorry for your shock and hope you get support processing it. I listen to a wonderful podcast called “DNA Surprises”. It covers all sorts of stories (like yours) and includes frequent issues/ experiences around it. It’s very supportive and inclusive.

This has to be a troll. There can't be any adult in 2026 who's never heard of paternity testing, or of crimes being solved by DNA evidence.