In characterizing Df(4)scH as part of my work with the Fourth Chromosome Resource Project, which is described in Weasner et al. (2025; https://doi.org/10.1093/g3journal/jkaf006), I found that it carries a mutation in bent (bt) that is likely unrelated to the fourth chromosome breakpoint in the progenitor aberration T(1;4)scH. This bt mutation will be denoted btH.