Marker Significance Chart

Y-Chromosome Marker Significance Chart

Variances in Y-chromosome DNA can affect the genetic distance calculated between individuals. The Y-Chromosome Marker Significance Chart is a compilation of information and resources on variables that impact the value of a marker, to include: "fast-moving" markers, nulls, RecLOH, etc.

KEY: S = Slow M= Medium F=Fast UNK=Unknown

DYS	Value	Rate	Significance
385a & 385b	11-11	F	Results are conventionally reported low-high, unless the physical order has been determined through testing originally designed by Kittler. Susceptible to RecLoH, Recombinant Loss of Heterozygosity. One copy of the 385 marker is lost and replaced by a copy of the other.
389-1 & 389-2		S	Primer L binds at one site on 389-1 and Primer R binds at two sites on 389-2; the marker name and results are reported in three different labs and academic studies. As an example, the following are equivalent results: Family Tree DNA: 389-1=12, 389-2=28; DNA Heritage: 389i=12, 389ii=28; Relative Genetics: 389I=12, 389II=28 Sorenson Molecular Genealogy Foundation: 389I=12, 385B=16 (i.e. 385B = 389-2 minus 389-1)) Oxford Ancestors: 389-i=9, 389-ii-i=16 (i.e. 389I minus 3) Also see: markers
439	12 (0)	F	Null 439s are assigned the predicted value of '12' within FTDNA's system, and are denoted null by a blue font and footnote. See: Null 439 Project
448	(0)	S-M?	Null 448s are assigned a predicted value within FTDNA's system. See: Null 448 Project
463			Nomenclature difference between Family Tree DNA and DNA Fingerprint - subtract '2' when entering value into Y-Search as of April 2007 - Source
464		F	A multi-copy marker and the numbers are always reported in the lowest to highest order. See: DYS464 464 is susceptible to palindromes; when one DNA strand nucleotide sequence is in the reverse order of its complementary strand. Example
464x		F	^{May be identified through testing DYF399S1 - an extended marker test developed by DNA-Fingerprint that can identify 464x using a SNP. See: 464x}
CDY a & b		F	Fastest moving markers; may mutate several times in one surname study.

Glossary of Marker Variable Causations

Back mutations - When a mutation goes in the reverse order.

Convergence - The coincidence of two different haplotypes' having the same mutations to appear similar. Occasionally, a haplotype's mutations cause it to appear similar to a haplotype in another haplogroup.

Null - A null is a value of zero on a marker. Nulls can occur due to missing genetic material on a marker, or a SNP can sometimes cause a null result. Several YSTR markers have been identified in certain families to have null results: 439, 448. When calculating genetic distance, disregard the assigned null value.

Palindromes - A segment of double-stranded DNA in which the nucleotide sequence of one strand reads in reverse order to that of the complementary strand.²

Parallel mutations - The same mutation occurring coincidentally in another line of descent from the MRCA (Most Recent Common Ancestor).

RecLOH - Acronym for Recombinant Loss of Heterozygosity - When a section of DNA on a marker is missing, that marker is sometimes repaired by another marker filling in the missing DNA with its own material. This is referred to as a "recLOH event" and is usually observed with multi-copy markers like 385a and 385b, and is also common in the 464 set. The recLOH event causes the allele values to match 11-11 instead of the more common, 11-14 that you see in R1b.

Mutation Rates:

Family Tree DNA's FTDNATiP mutation rates

Y-chromosome Marker Utilities:

Ann Turner's Mutation Rate Calculator

Dean McGee's Y-DNA Comparison Utility

Dennis Garvey's Allele Frequency Graphs by Y Haplogroup

Leo Little's Y-Search by FTDNA Haplotype

Leo Little's Y-STR Allele Frequencies

Thomas Krahn's YSTR Nomenclature Conversion Table