Incomplete penetrance of the predisposition to medulloblastoma associated with germ-line SUFU mutations

Methods and results: Germline SUFU mutations were identified in two families with several children under 3 years of age diagnosed with medulloblastoma. All medulloblastomas in which the histology was reviewed were of the desmoplastic subtype, including three with the rare extensive nodularity subtype. In both families, the mutation detected in the SUFU gene was a frameshift mutation. Among the 25 mutation carriers identified in the two families, seven developed medulloblastomas. Conclusions: This report highlights three features of SUFU related tumours. These are mainly medulloblastomas with extensive nodularity or typical desmoplastic/nodular medulloblastomas. These tumours mostly, if not exclusively, appear during the first 3 years of life. The penetrance of the mutation is incomplete.