Rhabdoid Tumours are aggressive pediatric malignancies which mainly develop in infancy and early childhood. When they arise in the central nervous system, they are referred to as atypical tetratoid/rhabdoid Tumours and malignant rhabdoid Tumours (MRT) when they arise in other renal and extrarenal sites. Most are associated with loss of function of the SMARCB1 gene in chromosome 22q11.2, and approximately one-third of patients with rhabdoid Tumours have a germline mutation in the SMARCB1 gene.
Incomplete penetrance and gonadal mosaicism has been described in families with such mutations, and relatives of affected cases may develop rhabdoid Tumours, schwannomas, or schwannomatosis (Eaton et al. 2011).