The present disclosure relates to processes for determining the number of nucleic acid repeats in a DNA fragment comprising a nucleic acid repeat region. One example method may include receiving DNA size and abundance data generated by resolving DNA amplification products. A set of low-pass data may be generated by applying a low-pass filter to the DNA size and abundance data and a set of band-pass data may be generated by applying a band-pass filter to the DNA size and abundance data. A peak of the DNA size and abundance data representative of a number of nucleic acid repeats in the DNA may be identified based on peaks identified from the low-pass data and the band-pass data.