Centromere attribute integration based chromosome polarity assignment.

Abstract

Automated karyotyping involves evaluating quantified chromosome attributes for proper classification. Chromosome attributes derived from the banding pattern require the correct chromosome polarity for correct banding sequence interpretation. Chromosome polarity is defined in terms of determining the short and long arms of the chromosome using the centromere as the reference point for measuring the chromosome length on both sides of the centromere. In addition to banding sequence interpretation, polarity is used in the chromosome orientation for chromosome repositioning from the metaphase spread to the karyotype. Automated polarity determination is often not performed for classifying chromosomes in the metaphase spread image. Polarity may be determined user interactively, by the system, or not at all. In order to reduce the computational complexity of evaluating banding sequence features using both chromosome ends as reference points, there is a need to improve chromosome polarity determination in automated karyotyping. A centromere attribute integration approach has been developed at the University of Missouri-Columbia which performs correct chromosome polarity assessment at a rate comparable to other studies of 96.1% on a diversified data set.