Significance of Cm Match (1346.16)

[tomtohioboy]

Did autosomal test for my older brother and I. We matched with count of 1346.16 Cm. This is lower than some half-sibling matches I've seen and I have gotten no (0) matches in Ancestry with my surname or other surnames on my father's side. Many matches on my mother's side. Many undetermined matches.
Any thoughts on these results?

[Mike McG]

Did autosomal test for my older brother and I. We matched with count of 1346.16 Cm. This is lower than some half-sibling matches I've seen and I have gotten no (0) matches in Ancestry with my surname or other surnames on my father's side. Many matches on my mother's side. Many undetermined matches.
Any thoughts on these results?

Tomtohioboy

You get half your autosomal genes from your mother and the other half is lost and similarly from your father. In theory, if your brother got his genes from the half that were lost, you would not match aDNA at all. In reality there is a distribution curve around the average predicted cM match value. You and your brother maybe be on the low side of that curve. Gedmatch would tell you where you and your brother match on both pair of your chromosomes, as well as give you additional matches. Unfortunately, I believe the site is down right now.

With respect to your lack of paternal matches (I presume this applies both to you and your brother), it may be he is from a small population or from a group that does not test much.

Mike McG


With respect to