Excellent yDNA matches (to 67 markers) exist between descendants of two of John's sons, along with a specially created branch on the yDNA haplogroup tree for them, and three other lines of Runciman families from the Borders and Lothians of Scotland
YFull yDNA branch where John's line is the I-A11399 sub branch, all the others (as at Jun 2017) under I-A22033 also being BigY tested Runciman branches from the Borders and Lothians.
Source: S2343 Will & Inventory: RUNCIMAN, James 1858, 1867, 1872, Testator: James RUNCIMAN (16766), Volume: SC60/41/24 (27 pp) & SC60/44/6 (2pp) Will written Jun 1858 codicil Dec 1867 Inventory 23 Feb 1872 proved 8 Mar 1872 Note: 27 page document containing the inventory and trust dispostion and settlement executed 8th Jun 1858, and codicil dated 27th Dec 1867. Also a 2 page document appointing the executors under the same Trust disposition and codicil Both downloaded Sep 2005 Repository: #R32 Call Number: Scotlands People
Repository: R32 New Register House, Edinburgh previously known as "General Registry Office"
Source: S2567 RUNCIMAN corres. between David (Spain) and Lorna Henderson (NZ)
It may be possible to confirm family relationships with John by comparing test results with other carriers of his Y-chromosome or his mother's mitochondrial DNA.
Y-chromosome DNA test-takers in his direct paternal line on WikiTree:
Please add a statement to this profile documenting the two matching Y-DNA tests used to confirm his relationship to his father, the number of markers the two test takers share, and the most recent common ancestor (MRCA) of the two. See this page for the format: Help:DNA_Confirmation#Y-Chromosome_Confirmation. Once that is done his father can be marked as confirmed with DNA.