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Help Advance Our Understanding of I-L38

Please consider ordering additional SNP tests


STEP 1. If you are:

STEP 2. Consider ordering these SNP Tests:



   L38+ or L39+ or L40+ or L65+

   S2606, S24121

   S2606+ and 24121+


   S2606+ and 24121-

   S2488, PH1237, Y18919


   L533, S27697


   No further tests available at this time


STEP 3. Ordering SNP tests:

  1. After you login to your personal FTDNA page, click the blue “Upgrade” button at the top right of your FTDNA Dashboard page.
  2. Scroll down to the “Advanced Tests” box on the left and click the “Buy Now” button.
  3. Select SNP under “Test Type” on the next page. Then, enter the desired SNP you wish to purchase for testing, repeat if ordering more than one SNP, and complete the purchase.


  • This project deals with a sub-group of the haplogroup called I which is known at the present time as I2a2b. The subclade of this Y-DNA haplogroup has been previously known as I(x), I1b2*, I2b* and I2b2. It can be defined by using SNP shorthand as L38+ (see paragraphs below for more information).
  • Haplogroup I-L38, then called I(x), was first described in May 2005 on the Genealogy-DNA list at Rootsweb.com. This consisted of several conversations between Bonnie Schrack and Ken Nordtvedt. Later they were joined by Glen Todd. 
  • Haplogroup I-L38 is sometimes nicknamed as the "Lichtenstein-haplogroup" because in the Lichtenstein cave, in the German Hartz mountains, 3000 year old bones were found that were typed as I2a2b.
  • Hans De Beule has set up a website decicated to I-L38


Introduction to SNPs and STRs

Like surnames, Y-DNA is being passed on from father to son. DNA itself is written in a 4 letter code (the letters G, C, A and T refer to the nucleotides: Guanine, Cytosine, Adenine and Thymine). Each time the DNA code is being copied (to be passed on from father to son) copy-errors might occur, characterizing the descendants of this line. A similar mechanism lead to variants of family names. For example, the Flemish family name Jansens became Janssens or Pieters became Peeters, … because of a copy-error. By studying the copy-errors (or more correct: mutations) on the Y-DNA, a paternal ancestral tree can be constructed.
The two types of copy-errors that can help to construct such a tree are:

  • Single Nucleotide Polymorphisms (SNPs, pronounced as “snips”) are copy-errors in the DNA code. During the copy-process of the code, a letter (nucleotide) was deleted, inserted or replaced by another letter.
  • Short Tandem Repeats (STR – “stutter mutations”) are changes in het number of repeats of pieces of code. These spare repeats can be seen as a sort of backup copies. For example: on the Y-chromosome-place “DYS448” the code AGAGAT of 19 repeats can mutate into 20 repeats: AGAGAT AGAGAT AGAGAT AGAGAT AGAGAT AGAGAT AGAGAT AGAGAT AGAGAT AGAGAT AGAGAT AGAGAT AGAGAT AGAGAT AGAGAT AGAGAT AGAGAT AGAGAT AGAGAT AGAGAT

A SNP-mutation is a unique copy-error that occurred in the Y-DNA code during the 200 000 years of humanity, while changes in the “stutter” of a STR occur more regular (on average every 200 generations). Due to their rareness and unicity SNP-mutations can be used as branching points of a paternal ancestral tree. Metaphorically SNPs are the main branches of the paternal tree, while the STR-mutations are the twigs and leaves at the ends of the branches.

About the naming of I-L38 (also known as I2a2b)
By studying the branching points of the paternal ancestral tree, it is possible to define haplogroups. This name comes from the Greek word haploûs, meaning - single. Haplogroups are groups that have a Single Nucleotide Polymorphism in common. SNP tests show whether a sample is positive or negative for a SNP mutation.
The result L38+ means that the sample does not have the ancestral state, but does have a derived, mutated state (for which it tests positive). In case of L38 this means that the ancestral allele “A” mutated into “G”. Because new SNPs are being discovered continiously, haplogroups become more detailed over time.
Each haplogroup can be further divided into clusters of haplotypes using STR values. There are two ways to refer to a haplogroup:

  1. By using the hierarchical name: According international naming conventions, letters and numbers alternate to appoint a haplogroup. For example: haplogroup I2b2 (aka I-L38) refers to branch “2” on branch “b” of branch “2” of haplogroup “I”. Disadvantage of this way of naming is that the entire hierarchical structure has to be adapted to fit in new discovered SNPs (with a confusion of tongues as a result). In 2011 I2a2b was called I2b2, before that it was called I2b*, and before that I2b1…  
  2. By using the determining mutation I-L38 refers to a branch of haplogroup I that is determined by mutation L38. Advantage of this way of naming is that it remains stable (samples remain positive or negative for a certain SNP). Y-DNA SNPs are referred to with a letter and a number. The letter refers to the lab or research team that discovered the SNP; the number indicates the order in which it was discovered. Eg: L38 was the 38th SNP that was discovered by the research team of Thomas Krahn of the Family Tree DNA Genomics Research Center. Sometimes separate research institutes discover the same mutation, which gets then two names. Eg: L38 and S154 refer to the same mutation (so haplogroup I-L38 could be called I-S154 as well).

SNP characteristics of haplogroup I-L38

Until now all haplotypes that tested positive on L38, also tested positive on L39/S155, L40/S156, L65/S159 and L272; thus haplogroup I-L38 also can also be defined (or named) using these SNPs. For reasons of clarity, haplogroup I-“L38/S154, L39/S155, L40/S156, L65/S159, L272” will be named "I-L38" here.

For the most recent tree: please refer to: https://sites.google.com/site/haplogroupil38/i-l38-snp-tree

STR characteristics of haplogroup I-L38
STR values represent the number of repeats at a certain DNA Y-chromosome Segment number (or DYS) that refers to a separate segment (in Latin locus) on the Y-chromosome.
Characteristic STR values of I-L38 are the DYS393=13 or 14, 426=11, 392=11, 459=8,10, 455=10 or 11, 454=12, YCAII= 19,19.
Because the genetic variety of the group is too small to separate valid clusters it is difficult to divide I-L38 using STR-values only.

I2a2b clusters and STR (and SNP) characteristics

Some STR values can be used to "predict" some of the SNP-subclades:

DYS454 DYS447 DYS448
S2606- 12 25 19
L533+ 11 25 19
S24121+ 12 24 19
It is good science to verify these predictions by testing the appropriate SNP