BAP1 Tumour Predisposition syndrome and the BAP1 gene

BAP1 tumour predisposition syndrome

BAP1 tumour predisposition syndrome is caused by mutation in the BAP1 gene. It is associated with melanocytic tumours, including melanoma, melanoma of the eye (uveal melanoma), malignant mesothelioma (a cancer of the lining of the chest cavity, usually associated with asbestos exposure), renal cell cancers (a type of kidney cancer) as well as basal cell carcinomas and atypical Spitz tumours.

Atypical Spitz tumours are skin-coloured to reddish-brown, averaging 5 mm in diameter. The histologic findings are between those of a Spitz nevus and a melanoma. In these tumours, both copies of the BAP1 gene are inactivated, leading to loss of staining for the BAP1 protein on immunohistochemistry. This may be a clue to an inherited BAP1 mutation.

BAP1 tumour predisposition is very rare, with less than 100 families known worldwide. As a result, scientists are still trying to determine the lifetime cancer risk and Australian risk management guidelines have not yet been developed.

Individuals with a BAP1 mutation should follow sun sense guidelines and avoid arc welding due to the risk of uveal (eye) melanoma.

Genetic testing for germline BAP1 mutations should be considered if there are two or more confirmed BAP1-associated tumours (excluding BCC or cutaneous melanoma) or if there is loss of staining for the BAP1 protein in IHC testing.

There is a 50% chance of a person who carries a germline BAP1 mutation, whether male or female, passing the mutation to their son or daughter. If a mutation is identified, then predictive testing is available for blood relatives.

Does this sound like you or your family? Has a BAP1 mutation been detected in a blood relative? Make an appointment with Dr Hilda High at Sydney Cancer Genetics. It is a confidential opportunity to discuss your personal and family history of cancer and genetic testing can be organised, if needed. You'll find information on how to make an appointment here

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