Tri-Allelic Patterns

Three-banded or tri-allelic patterns are sometimes observed at a single locus in a multiplex STR profile. These tables of tri-allelic patterns are for scientists to "compare notes" as well as to see if certain allele combinations are more likely. Tri-allelic patterns generally fall into one of two different groups based on relative peak heights:

 

Type 1: Sum of heights of two of the peaks is equal to the third

Type 2: Balanced peak heights

We welcome your contributions in order to more fully catalog the genetic variation observed in these STR loci.

To contribute to these tri-allelic variant reports, click here.

176 total patterns reported as of 08/07/2008

[click on loci listed below for details]

Core STR Loci

�         CSF1PO (7)

�         FGA (22)

�         TH01 (3)

�         TPOX (15)

�         VWA (19)

�         D3S1358 (7)

�         D5S818 (6)

�         D7S820 (7)

�         D8S1179 (11)

�         D13S317 (8)

�         D16S539 (7)

�         D18S51 (23)

�         D21S11 (19)

 

 

 

Other Common STR Loci

�         D2S1338 (3)

�         D19S433 (2)

�         Penta D (5)

�         Penta E (11)

�         F13A01

�         FES/FPS (1)

�         F13B

�         LPL

�         SE33

 

 

 

 

 

 

 

Y-STR Loci

�         DYS19

�         DYS389I

�         DYS389II

�         DYS390

�         DYS391

�         DYS392

�         DYS393

�         DYS385 a/b

�         DYS438

�         DYS439

�         DYS437

�         DYS448

�         DYS456

�         DYS458

�         DYS635/GATA-C4

�         Y-GATA-H4

 

Variant Alleles

Information on Variant STR Alleles Sequenced at NIST

Some useful references with more information on tri-allelic patterns include:

Crouse et al. (1999) Analysis and interpretation of short tandem repeat microvariants and three banded allele patterns using multiple allele detection systems [published erratum appears in J. Forensic Sci. 1999 May;44(3)].  J. Forensic Sci. 44(1):87-94. They report finding 18 TPOX three-banded patterns, and one CSF1PO three-banded pattern.

Clayton et al. (2004) A genetic basis for anomalous band patterns encountered during DNA STR profiling. J Forensic Sci. 49(6):1207-1214.  They introduce the "Type 1" and "Type 2" nomenclature for tri-allelic patterns.

Butler, J.M. (2006) Genetics and genomics of core STR loci used in human identity testing. J. Forensic Sci. 51(2): 253-265.

 

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