U.S. flag

An official website of the United States government, Department of Justice.

Principles of Forensic DNA for Officers of the Court

Y-STR Statistical Analysis

Home  |  Glossary  |  Resources  |  Help  |  Contact Us  |  Course Map

illustration of some equations
National Institute of Justice (NIJ) (see reuse policy).

As a result of these factors, the degree of inter-individual Y-chromosome variation is substantially reduced compared to the autosomes.

  • A typical autosomal STR profile may have an expected frequency of occurrence in 1 in every 100 trillion individuals (10 -14 ), whereas a typical Y- STR profile may occur in 1 in every 1000 individuals (10 -3 ).

Back Forward