INTRODUCTION: An ovarian Sertoli cell tumour was detected in a 4-year-old girl with gonadotrophin-independent precocious puberty. Such gonadal tumours can be associated with Peutz-Jeghers syndrome, caused by mutations in the STK11 gene. We have therefore sequenced the STK11 gene.
RESULTS: Mutation analysis revealed a nonsense mutation in exon 1 (c.130A>T;p.Lys44X) of the SKT11 gene, which resulted in a truncated, inactive protein. The mutation was heterozygous in patient's lymphocytes and almost homozygous in the tumour, indicating loss of heterozygosity.
CONCLUSION: This is the first report of a STK11 germline mutation in a girl with an ovarian Sertoli cell tumour. It remains to be shown whether this particular mutation predisposes the patient to the development of ovarian tumours.