Son has more DNA with a shared match than my mum and me

[Lisa in California]

Hello.  I don't understand much about DNA  but I do understand how siblings can acquire varying amounts from their parents.  Is the same true for any family member, please? 

In a last ditch effort to find a few brickwall answers, my mum, brother, younger (adult) son and I all had DNA tests done.  Overall, I am pleased that we all took the tests.

Looking at one DNA match with a possible distant relative, I noticed that my son has more cM than any of us:
Mum - 13 cM, 1 seg
Brother - Not a match
Me - 8 cM, 1 seg
Son - 14 cM, 1 seg

I understand how my brother could not be a match, but is it common for a grandchild to have a tiny bit more cM than his grandmother (and mother)?  Apologies for what most likely is a silly question.  Thank you in advance for any guidance that you might be able to share.  Lisa

[shellyesq]

I don't know much about the numbers, but could it be that your son has a distant connection to the same person through one of his father's ancestors?

[Lisa in California]

Hi Shelly:  Thank you so much for your reply.  My husband also had his DNA tested (he did it to please me as he is bored to tears with genealogy)  .  I just checked to see if he is also a match to this other person, and he is not.  So, that should rule out that possibility?  Thank you for suggesting it, as it would have been fun to have searched for our connection.

I am assuming our match is through our "Ovens" ancestors as that name is in our family trees and his Ovens settled in the same Canadian province as our Ovens.

If anyone might be able to tell me, please, if it is somewhat common for a grandchild to have about the same or the tiniest bit more DNA than a grandparent, I would be very grateful.  I suppose there could be slight errors in the testing that could account for the numbers to be a bit off?  (I did try googling my question, but after a somewhat quick search, I could not find any answers.)

Thank you again, Shelly.  (I miss helping on the USA and Canada boards; I hope to be back after we've moved and had a chance to settle in.  Break over, back to painting.)

[IgorStrav]

These cM matches are very small, and I think the differences between your son's match with the distant relative and yours and your Mum's are insignificant.

DNA cM matches show wide ranges within the same relationship.

I don't think on this occasion it's particularly likely that the difference in shared cM is owing to a match via his father.

However, no harm in checking!

[Lisa in California]

IgorStrav:  Thank you for your reply.    I will move on to seeing if and how our Ovens could be related.

We've been hunting around for our elusive Ovens ancestors since our first (my only) trip to Ireland when I was a teenager.

Thank you IgorStrav; now I won't be curious about little differences.