Comprehensive Study of the Clinical Phenotype of Germline BAP1 Variant-Carrying Families Worldwide.

Walpole S, Pritchard AL, Cebulla CM, Pilarski R, Stautberg M, Davidorf FH, de la Fouchardière A, Cabaret O, Golmard L, Stoppa-Lyonnet D, Garfield E, Njauw CN, Cheung M, Turunen JA, Repo P, Järvinen RS, van Doorn R, Jager MJ, Luyten GPM, Marinkovic M, Chau C, Potrony M, Höiom V, Helgadottir H, Pastorino L, Bruno W, Andreotti V, Dalmasso B, Ciccarese G, Queirolo P, Mastracci L, Wadt K, Kiilgaard JF, Speicher MR, van Poppelen N, Kilic E, Al-Jamal RT, Dianzani I, Betti M, Bergmann C, Santagata S, Dahiya S, Taibjee S, Burke J, Poplawski N, O'Shea SJ, Newton-Bishop J, Adlard J, Adams DJ, Lane AM, Kim I, Klebe S, Racher H, Harbour JW, Nickerson ML, Murali R, Palmer JM, Howlie M, Symmons J, Hamilton H, Warrier S, Glasson W, Johansson P, Robles-Espinoza CD, Ossio R, de Klein A, Puig S, Ghiorzo P, Nielsen M, Kivelä TT, Tsao H, Testa JR, Gerami P, Stern MH, Paillerets BB, Abdel-Rahman MH, Hayward NK
J Natl Cancer Inst 110 1328-1341 12/01/2018

Abstract

Background: The BRCA1-associated protein-1 (BAP1) tumor predisposition syndrome (BAP1-TPDS) is a hereditary tumor syndrome caused by germline pathogenic variants in BAP1 encoding a tumor suppressor associated with uveal melanoma, mesothelioma, cutaneous melanoma, renal cell carcinoma, and cutaneous BAP1-inactivated melanocytic tumors. However, the full spectrum of tumors associated with the syndrome is yet to be determined. Improved understanding of the BAP1-TPDS is crucial for appropriate clinical management of BAP1 germline variant carriers and their families, including genetic counseling and surveillance for new tumors.

Methods: We collated germline variant status, tumor diagnoses, and information on BAP1 immunohistochemistry or loss of somatic heterozygosity on 106 published and 75 unpublished BAP1 germline variant-positive families worldwide to better characterize the genotypes and phenotypes associated with the BAP1-TPDS. Tumor spectrum and ages of onset were compared between missense and null variants. All statistical tests were two-sided.

Results: The 181 families carried 140 unique BAP1 germline variants. The collated data confirmed the core tumor spectrum associated with the BAP1-TPDS and showed that some families carrying missense variants can exhibit this phenotype. A variety of noncore BAP1-TPDS -associated tumors were found in families of variant carriers. Median ages of onset of core tumor types were lower in null than missense variant carriers for all tumors combined (P < .001), mesothelioma (P < .001), cutaneous melanoma (P < .001), and nonmelanoma skin cancer (P < .001).

Conclusions: This analysis substantially increases the number of pathogenic BAP1 germline variants and refines the phenotype. It highlights the need for a curated registry of germline variant carriers for proper assessment of the clinical phenotype of the BAP1-TPDS and pathogenicity of new variants, thus guiding management of patients and informing areas requiring further research.

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