Y-chromosome DNA shared by men with 6 names that match names in ancient pedigrees of men descended from Breassal Breac, King of Leinster around 200 or 100 BC.  All who have BIG Y test results share the Y5058 SNP and many other unique SNPs downstream of R-P312 and DF27.

Key STR markers: 481=24, 520=21.

Recent Y-chromosome DNA tests at Family Tree DNA show a similarity in DNA between men with the surnames O'Dwyer and Ryan. A 17th century history of Ireland connects these two names genealogically in Munster and ultimately back to Leinster. People with other names have been found to have this DNA as well: Carroll/McCarvill, Lee/Leary, Kennedy/Cannady, Gorman, Keogh/Cahoo. People who have this DNA are invited to join.

See the Breassal Breac web page