Germ cell tumours in a brother and sister

In familial germ cell tumour cases, a normal chromosomal karyotype pattern is rare. We report the findings of germ cell tumours in two siblings with a normal chromosomal karyotype. One of these patients had dysgerminoma in the right ovary and was treated successfully for this. At present, she is 23 years old and has two daughters. The other patient is a 15-year-old boy, who is the brother of the first patient and has mediastinal embryonal carcinoma. Although ultrasonography of the testes showed irregularity in the shape and non-homogeneity of the parenchyma, histopathological examination was found to be normal at the time of diagnosis. At present, he is doing well and his chemotherapy is continuing. Both of them have a normal chromosomal karyotype, 46, XX and 46, XY, respectively. We suggest that children who have a sibling with germ cell tumour should be carefully assessed for development of another germ cell tumour.