Assessing time-dependent changes of GAA tract length in FRDA lymphocytes.

Abstract

<p>(<b>A</b>) The GAA repeat tract at the <i>FXN</i> locus was amplified using genomic DNA extracted from lymphocytes, which were isolated from 5 patients (F10, F11, F12, M7 and F13). Blood samples were taken at an initial timepoint (I) and a second time point 7–9 years after the initial sampling (II) (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0189990#pone.0189990.t003" target="_blank">Table 3</a>). The time-dependent changes in GAA repeat length were quantitated as (<b>B</b>) total GAA repeat gain/loss (ΔGAA) and (<b>C</b>) rate of the change (ΔGAA per year). (<b>D</b>) The Pearson’s correlation coefficient was calculated using the size of the GAA tract at time point I [GAA(I)] and the change of the number of GAAs between time points II and I [ΔGAA (II-I)]. Five pairs of samples (n = 10 alleles) were analyzed.</p