Genetic Disorder Reference Sheet: BAP1

January 17, 2023 by Suzanne M. Mahon DNS, RN, AOCN®, AGN-BC, FAAN

Isolated in 1998 as a tumor suppressor gene, BAP1 pathogenic variants have been identified ( in at least 200 families. More cases will be found as germline pathogenic variant testing becomes more readily available and routinely offered to patients with cancer.

Cancer Risk

BAP1 pathogenic variants are associated with increased risk ( for malignancies and tumors. BAP1 tumor predisposition (BAP1-TPDS) characteristics ( include:

Other cancers that may be associated with BAP1 pathogenic variants include multiple basal cell skin cancers, breast cancer, cholangiocarcinoma, meningioma, neuroendocrine tumors, non-small cell lung adenocarcinoma, and thyroid cancer, but the risk is not understood.

Biomarker Testing

Germline biomarker testing should be offered to any individual with two or more BAP1-TPDS characteristics or individuals with a BAP1-TPDS characteristic and a relative with one BAP1-TPDS characteristic (excluding two basal cell cancers or cutaneous melanomas because of their high frequency in the general population). First- and second-degree relatives of people with known BAP1 pathogenic variants should also be offered testing.

Prevention and Early Detection

Intensive surveillance ( can lead to early detection ( when treatment is most likely to be effective. People with BAP1 pathogenic variants should obtain annual:

Educate patients about lifestyle prevention measures, including:

Mesothelioma has no reliable early disease symptoms or screening modalities, but people with BAP1 pathogenic variants should obtain annual physical examinations for late manifestations, including chest pain, cough, fever, shortness of breath, dysphagia, hoarseness, weight loss, fever, upper body and face edema, abdominal pain, ascites, nausea, vomiting, and constipation.

Implications for Nurses

Because screening measures are recommended for children, families with known pathogenic BAP1 variants should consider testing at age 10. Credentialed genetics professionals can assist families with that process.

BAP1 is a susceptibility biomarker ( that indicates a person’s potential for developing multiple malignancies. Identifying the pathogenic variant in those individuals allows them to consider more intensive surveillance and prevention measures and potentially reduce morbidity and mortality.

It also serves as a prognostic biomarker ( People with a germline BAP1 pathogenic variant tend to live longer with mesothelioma, suggesting it is a less aggressive form, whereas those with uveal melanoma may have a poorer prognosis.

However, its value as a predictive biomarker ( is limited at this time: Mesothelioma, metastatic uveal melanoma, metastatic renal cell carcinoma, and other BAP1-related malignancies are resistant to current therapies and are an active area of research (

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