Biomedical subjects

Kylee H Maclachlan

Publications and source records attributed to Kylee H Maclachlan.

3 recordsLinked to original sources

PubMed2026

Genomic Features Do Not Account for Differences in Multiple Myeloma Risk by Ancestry.

UNLABELLED: Studies have reported conflicting findings regarding the contribution of germline variants or somatic genomic drivers to racial disparities in multiple myeloma. To comprehensively investigate somatic drivers in relation to inherited genetics in multiple myeloma, we combined newly sequenced whole-genome sequencing data with publicly available datasets (total n = 1,286). Overall, we did not identify germline or somatic genomic differences that explain the different risk of developing multiple myeloma between patients with genetic similarity to African (AFR) or European (EUR) reference populations. A difference in the detectability and timing of APOBEC-associated and germinal center mutational activity was observed. Integrating epidemiologic data and mutational signature-based temporal estimates, we challenge the assumption that individuals in the AFR group develop multiple myeloma at a younger age. Finally, we demonstrate that, with equal access to efficacious therapies, patients in the AFR and EUR groups have equivalent clinical outcomes. SIGNIFICANCE: Multiple myeloma is reported to occur at higher rates in individuals who self-identify as non-Hispanic Black. In this large dataset, genomic drivers occur at the same rate among ancestry groups, except for APOBEC mutagenesis. With equivalent therapy, clinical outcomes did not differ for patients grouped by genetic ancestry similarity.

Humans↗

PubMed2025

Mutagenic Impact and Evolutionary Influence of Chemoradiotherapy in Hematologic Malignancies.

UNLABELLED: Ionizing radiotherapy (RT) is a widely used treatment strategy for malignancies. In solid tumors, RT-induced double-strand breaks lead to the accumulation of insertion-deletions (indels; ID), and their repair by nonhomologous end joining has been linked to the ID8 mutational signature in surviving cells. However, the extent of RT-induced mutagenesis in hematologic malignancies and its impact on their mutational profiles and interplay with commonly used chemotherapies has not yet been explored. In this study, we interrogated 580 whole-genome sequence (WGS) samples from patients with large B-cell lymphoma, multiple myeloma, and myeloid neoplasms and identified ID8 only in relapsed disease. Yet ID8 was detected after exposure to both RT and mutagenic chemotherapy (i.e., platinum and melphalan). Using WGS of single-cell colonies derived from treated lymphoma cells, we revealed a dose-response relationship between RT and platinum and ID8. Finally, using ID8 as a genomic barcode, we demonstrate that a single RT-surviving cell may seed distant relapse. SIGNIFICANCE: RT and the ID8 indel signature are related, but their genomic impact on hematologic malignancies is unclear. Leveraging WGS, we linked ID8 to both RT and mutagenic chemotherapy and validated that platinum can induce ID8. We used ID8 as a genomic barcode to reveal that RT-resistant cells may seed systemic relapse.

Humans↗

PubMed2021

Whole-genome sequencing reveals progressive versus stable myeloma precursor conditions as two distinct entities.

Multiple myeloma (MM) is consistently preceded by precursor conditions recognized clinically as monoclonal gammopathy of undetermined significance (MGUS) or smoldering myeloma (SMM). We interrogate the whole genome sequence (WGS) profile of 18 MGUS and compare them with those from 14 SMMs and 80 MMs. We show that cases with a non-progressing, clinically stable myeloma precursor condition (n = 15) are characterized by later initiation in the patient's life and by the absence of myeloma defining genomic events including: chromothripsis, templated insertions, mutations in driver genes, aneuploidy, and canonical APOBEC mutational activity. This data provides evidence that WGS can be used to recognize two biologically and clinically distinct myeloma precursor entities that are either progressive or stable.

DNA Copy Number Variations↗