Abstract 258: Whole genome analysis of hereditary leiomyomatosis and renal cell cancer identifies role of localized hypermutational events

Abstract

Abstract Hereditary leiomyomatosis and renal cell cancer (HLRCC) is a rare hereditary condition affecting over 1 in 200,000 people worldwide. Individuals with HLRCC are also at risk of developing an aggressive form of renal cell carcinoma (RCC), as 15-20% of patients develop type 2 papillary RCC associated with poor prognosis. Although RCC risk and cancer penetrance of this condition has been studied, whole genome sequencing of associated tumors has yet to be examined, and the landscape of structural variants of HLRCC is largely unknown. We have therefore performed whole genome sequencing of tumor/normal pairs of HLRCC patients to study the tumor molecular architecture in this form of RCC. Through germline variant and somatic mutation calling, we have identified specific somatic mutational drivers, including those at the structural variant level for the first time in HLRCC. We have also quantified both chromothripsis and kataegis in these tumors, identifying the specific role of localized hypermutational events. Similarly, using tumour subclonal reconstruction techniques, we have inferred the clonality of HLRCC-associated RCC tumors and elucidate the relative timing of key oncogenic events and mutational processes. We also compare each of these mutational features to their equivalents in other RCC tumour subtypes. These studies shed key light on the specific mutational processes and drivers of this rare hereditary malignancy and on its lethality. Citation Format: Selina Wu, Paul C. Boutros. Whole genome analysis of hereditary leiomyomatosis and renal cell cancer identifies role of localized hypermutational events [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 258.