On 23&me the DNA results came in yesterday and it exactly states "You & John share the DNA that was passed down from two of your grandparents (his parents)". We have 331cm in common at 4.45%. I am 75yrs old, so this Uncle must be around my age. Doesn't 331 cm seem too low to be my Uncle? what other relative can this be? I supposedly knew all my uncles & aunts.
Yes, 331cM seems too low to be an uncle. Uncles/Aunts are usually in the 1200 -> 2200 cM range.
DNAPainter's Shared centiMorgan tool is a great way to look at possible relationships.
For 331cM of shared DNA, it suggests the following possible relationships:
- [48%] Half GG-Niece/Nephew or Half GG-Aunt/Uncle or 2C or Half 1C1R or 1C2R
- [46%] Great-Great-Aunt/Uncle or Half Great-Aunt/Uncle or Half 1C or 1C1R or Half Great-Niece/Nephew or Great-Great-Niece/Nephew
- [ 6%] 1C3R or Half 1C2R or Half 2C or 2C1R