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First identified in 2009, (formerly ) is an emerging multidrug resistant fungus that can cause invasive infections with a crude mortality rate ranging from 30-60%. Currently, 30-50% of isolates are intrinsically resistant to amphotericin B. In this work, we characterized a clinical case of acquired amphotericin B resistance using whole genome sequencing, a large-scale phenotypic screen, comprehensive sterol profiling, and genotypic reversion using CRISPR. Data obtained in this work provides evidence that a deletion resulting in a frameshift in contributes to the observed resistant phenotype. Characterization of this isolate also revealed a fitness cost is associated with the abrogation of ergosterol production and its replacement with other late-stage sterols. This article presents a clinical case description of amphotericin B resistance from a frameshift mutation in in and marks an advancement in the understanding of antifungal resistance in this fungal pathogen.