HG-101: HIGH GRADE GLIOMA IN TWO SIBLINGS

We report the cases of two sibs of different ages with café-au-lait spots, who were diagnosed with a high-grade glioma (HGG), both at the age of seven years old. One of the HGG was located in the right frontal area of the brain and the other in the left temporal area. Both of the cases had an unfavorable evolution, as expected, and death occurred at three years and eighteen months after diagnosis, respectively. They had initially the diagnosis of neurofibromatosis type 1 that was questioned after the death of the second sibling. Immunohistochemistry of the tumor tissue from one of the sibs was performed and no alterations were found. We proceed with the study of the parents by Sanger sequencing of the genes PMS2, MSH6, MLH1 and MSH2 in blood samples which revealed, in both progenitors, the presence of the c.989-2A> G in heterozygosity in intron 9 of the PMS2 gene. That allowed the diagnosis of Turcot syndrome in both sibs. Family history revealed a maternal uncle with an adenocarcinoma of the colon at 38 years old, a paternal grand-father with a prostate cancer at 60 years old and a brother of this relative with a cholangiocarcinoma at 53 years old. A molecular prenatal diagnosis might allow an earlier and more accurate diagnosis. The identification of relatives with increased neoplastic risk is important so they can benefit from a surveillance program with specific recommendations.