What is a Short Tandem Repeat (STR)?
Learning Center» Paternal Ancestry (Y-DNA)» Y-DNA STR» What is a Short Tandem Repeat (STR)?
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STR Overview

A short tandem repeat (STR) is a type of DNA polymorphism where short sequences of DNA are repeated. STRs are usually considered “junk DNA” because they are introns and do not code for protein. The number of times a DNA sequence is repeated for a given STR is variable between different individuals and thus, STRs are often useful for forensic or genealogical studies.


The STRs found in the Y-DNA are very useful for genealogical studies to examine male lineage. A male individual’s Y-DNA STR is unique to his paternal line and can be determined through Y-DNA STR Testing. That means that all males who are descendents from the same male lineage will have exactly the same or a very similar Y-DNA STR pattern.

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What is a Short Tandem Repeat (STR)?. Genebase Tutorials. Retrieved November 27, 2014, from http://www.genebase.com/learning/article/63
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