In the case of J1c, it is mentioned in the text that a sublineage J1c2d, defined by a transition in site 16366, is common among Basques and that this particular lineage has also been found in some other populations, specifically the Irish (McEvoy et al. 2004).
Besides these two, the most common mtDNA lineages among Basques are H1, H3 and V. Among these, this paper finds that sublineages H1j1 and V10 are notably common in the country.
Overall and based in an array of older papers, the authors feel that they must support the post-LGM recolonization theory, which would have originated from a
Franco-Cantabrian refuge. However they argue that U5b1b, which has been claimed to be of similar origin for being found in remote populations such as the Berbers or Saami (Achilli et al. 2005) has not been found in their survey of (a fraction) of the Franco-Cantabrian refuge. Here I must say that while the datum is surely valid, the argument is somewhat weak however because they have not sampled all the Franco-Cantabrian refuge but just a small fraction: 2/3 of what is now France remain largely unresearched.