In This Site

Connemara Harbour

Site Map of Irish Type III

Irish Type III Home Page

Here we discuss the R1b haplogroup and various clusters within it including the Atlantic Modal Haplotype (AMH). A brief explanation of the Irish Type III cluster is given, definitive STRs and SNPs together with its Origins and Age

Results for Irish Type III

These three pages that show the STR marker values found for members of the cluster, their Spread and SNP markers found for the cluster.

      º STR Markers Results

            ºSTR Marker Spreadsheet a downloadable (pdf) table of STR results

      º SNP Markers

      º Spread

Origins of the Irish Type III cluster

A table showing the Irish counties from which the cluster originated which are then summarised in a Counties map of Ireland

Surnames in the Irish Type III cluster

As the Irish Type III is the signature of the Dal gCais sept, it is dominated by surnames such as O'Brien, Hogan, Casey and Kennedy, but there are many other surnames found to have these markers.

      º Frequency This page shows every Surname found and how often it has occurred in the database

      º Notes For some Surnames, additional notes show possible origins or reasons for that name being Irish Type III.

Irish Eyes

A very occasional newsletter bringing items of interest to the members of the Irish Type III cluster.

      º Irish Eyes # 1 18 May 2007

      º Irish Eyes # 2 11 June 2007

      º Irish Eyes # 3 16 July 2007

      º Irish Eyes # 4 04 September 2007

      º Irish Eyes # 5 04 October 2007

      º Irish Eyes # 6 05 November 2007

      º Irish Eyes # 7 14 December 2007

      º Irish Eyes # 8 14 February 2008

      º Irish Eyes # 9 21 March 2008

      º Irish Eyes # 10 30 May 2008

      º Irish Eyes # 11 20 Sept 2008

      º Irish Eyes # 12 22 December 2008

      º Irish Eyes # 13 09 May 2009

      º Irish Eyes # 14 03 November 2009

      º Irish Eyes # 15 08 July 2010

      º Irish Eyes # 16 09 April 2011

      º Irish Eyes # 17 29 July 2012

      º Irish Eyes # 18 2 June 2013

      º Irish Eyes # 19 10 November 2013


Books that will be of interest to those searching in Genetic Genealogy.

Convert Markers

As some laboratories report some markers differently, this page shows what adjustments should be made before entering results in Ysearch.

      º ySearch Database Update

Walk The Y

Thomas Krahn ran a project at FTDNA to find new SNPs. This page shows how it has found the defining SNP for the Irish Type III cluster.

Big-Y Testing

FTDNA is now using NGS (Next Generation Sequencing)to find new SNPs. This page shows how Big-Y has found new SNPs and branches for the Irish Type III cluster.


Here are many links to pages of interest to Genetic Genealogists. Some pages are held on this website, see below.

      º Ken Nordtvedt's R1b Varieties and their Modal Haplotypes

      º Debbie Kennett's DNA Primer

      º ySearch Database Update

      º Dalcassian Paper at JoGG (pdf file)

      º Supplementary Data for JoGG Paper (Excel file)


How I became involved in Genetic Genealogy and set up this website for our cluster.

Lost Members

Listing of cluster members who, have changed email addresses, or have been FTDNA or Ancestry tested but are unaware of their Irish Type III roots.