MRC1 and colorectal carcinoma: Vasen et al (1996) suggested that the possible histological types of brain tumours that can occur in HNPCC kindreds include astrocytomas, oligodendrogliomas and rarely ependyomas. Other studies have reported germline MMR gene mutation in four patients with Turcot syndrome; three reported that a close relative had had CRC (Vasen et al, 1996; Miyaki et al, 1997; Hamilton et al, 2002).