SNP-defined subgroups Subgroup
G1a (P20) is rather common among G1 persons, but the reliability of SNP P20 in identifying G1a persons makes some tests for P20 a problem. P20 results may be reported as P20.1, P20.2 and P20.3, and persons may have varying results for each. The technical features of P20 are: Y position is 25029911; 23396163.....forward primer is .....reverse primer is ...the mutation is a deletion of C. Category G1a has a separate subgroup based on the presence of the value of 8 at
short tandem repeat marker DYS494. With the exception of this G1a subgroup, all other G persons have 9 at this slowly mutating marker. So far about half of G1a persons who are otherwise ungrouped have this 8 value.
G1a1 (L201, L202 and L203) were identified in a G1a person tested at
Family Tree DNA in fall 2009, Subsequent testing showed that only some G1a persons have these mutations, and so far they are all from a closely related
Ashkenazi Jewish cluster of men. The following Y positions were noted: 2718285 for L201, 13001714 for L202 and 13001715 for L203. In L201 the mutation is C to T; in L202 from T to C; and in L203 from A to G. If any man should have one of these SNP mutations without the others, this information would become the basis of a new G1a1 classification.
Old G1b (P76) was removed from the official listing in August, 2012, because its discovery in a single person makes it so far only a private SNP.
G1b (L830, L831, L832, L834, L835) were identified in late 2011 at
Family Tree DNA. The G1c mutations are: L830 (T to C at position 6923908), L831 (T to C at position 6991562), L832 (T to G at position 12796626), L834 (T to A at position 16019950), L835 (G to A at position 16291409).
STR marker value clusters There exist two distinctive European-ancestry
Ashkenazi Jewish clusterings within G1a1 and G1c and a distinctive G1a Kazakh cluster—all three based on
short tandem repeat (STR) marker values. Men in the Jewish G1c cluster have a value of 12 at STR marker DYS446 which is several values lower than almost all G persons, but the other two groups lack one specific marker value as an identifier. When approximately 30 or more STR markers are available when comparing samples, members in each of the three groups are easily ascertained. One of the distinctive European-ancestry G1c Ashkenazi Jewish STR marker value combinations is also found in an Iraqi Jew in one research study. See also the page covering
Jews with Haplogroup G (Y-DNA). Among the available 67-marker G1 STR samples, the Ashkenazi G1a1 Jewish cluster represents the closest relatives to the Kazakh G1a cluster based on similarity of STR marker values. The Ashkenazi G1c cluster is only distantly related to the Ashkenazi G1a1 cluster, and the G1c Ashkenazi cluster has nearest relatives instead among diverse Europeans. ==Migrations of G1 persons==