Statistics Papers

Document Type

Journal Article

Date of this Version

2011

Publication Source

Annals of Applied Statistics

Volume

5

Issue

2A

Start Page

645

Last Page

668

DOI

10.1214/10-AOAS400

Abstract

Given a set of aligned sequences of independent noisy observations, we are concerned with detecting intervals where the mean values of the observations change simultaneously in a subset of the sequences. The intervals of changed means are typically short relative to the length of the sequences, the subset where the change occurs, the “carriers,” can be relatively small, and the sizes of the changes can vary from one sequence to another. This problem is motivated by the scientific problem of detecting inherited copy number variants in aligned DNA samples. We suggest a statistic based on the assumption that for any given interval of changed means there is a given fraction of samples that carry the change. We derive an analytic approximation for the false positive error probability of a scan, which is shown by simulations to be reasonably accurate. We show that the new method usually improves on methods that analyze a single sample at a time and on our earlier multi-sample method, which is most efficient when the carriers form a large fraction of the set of sequences. The proposed procedure is also shown to be robust with respect to the assumed fraction of carriers of the changes.

Keywords

scan statistics, change-point detection, segmentation, DNA copy number

Share

COinS
 

Date Posted: 27 November 2017

This document has been peer reviewed.