Dear Ann, The amount of DNA that two distant cousins share in common can vary substantially. You are seeing a manifestation of that here. In some cases one sibling will share quite a bit of DNA with a specific distant cousin (but still within specific parameters depending on the genealogical relationship) and another sibling will share little or none. Sincerely, Tim Janzen -----Original Message----- From: autosomal-dna-bounces@rootsweb.com [mailto:autosomal-dna-bounces@rootsweb.com] On Behalf Of AGilchrest@aol.com Sent: Friday, December 13, 2013 8:34 PM To: autosomal-dna@rootsweb.com Subject: [AUTOSOMAL-DNA] Drastic difference in segment size I am looking at a segment match between my mother and her sister and a Mr. Smith. The match is as follows: Mom & Mr. Smith match on Chromosome 4 start position 126699718 end position 138696900. cM's 8.80, Total SNP's 2100 My Aunt & Mr. Smith match on Chromosome 4 start position 81630475 end position 138696900 cM's 46.80, Total SNPs 11,157 This is the first time I have seen such a huge difference in a match. Is this due to recombination? And how siblings may receive there DNA? Thank you, Ann Gilchrest