MedGen

Schwannomatosis is characterized by a predisposition to develop multiple schwannomas and, less frequently, meningiomas. Individuals with schwannomatosis most commonly present between the second and fourth decade of life. The most common presenting feature is localized or diffuse pain or asymptomatic mass. Schwannomas most often affect peripheral nerves and spinal nerves. Meningiomas occur in about 5% of individuals with schwannomatosis and have only been reported in individuals with SMARCB1-related schwannomatosis. Malignancy remains a theoretic risk especially in individuals with a SMARCB1 pathogenic variant. [from GeneReviews]

Coffin-Siris syndrome is a congenital malformation syndrome characterized by developmental delay, intellectual disability, coarse facial features, feeding difficulties, and hypoplastic or absent fifth fingernails and fifth distal phalanges. Other more variable features may also occur. Patients with SMARCB1 mutations may have more severe neurodevelopmental deficits including severe intellectual disability, brain structural abnormalities, and no expressive words, as well as scoliosis (summary by Kosho et al., 2014). For a general phenotypic description and a discussion of genetic heterogeneity of Coffin-Siris syndrome, see CSS1 (135900). [from OMIM]

The rhabdoid tumor predisposition syndrome is an autosomal dominant cancer syndrome predisposing to renal or extrarenal malignant rhabdoid tumors and to a variety of tumors of the central nervous system, including choroid plexus carcinoma, medulloblastoma, and central primitive neuroectodermal tumors (Sevenet et al., 1999). Rhabdoid tumors are a highly malignant group of neoplasms that usually occur in children less than 2 years of age. Malignant rhabdoid tumors (MRTs) of the kidney were first described as a sarcomatous variant of Wilms tumors (Beckwith and Palmer, 1978). Later, extrarenal rhabdoid tumor was reported in numerous locations, including the central nervous system (CNS) (Parham et al., 1994). Classification has been difficult because of considerable variation in the histologic and immunologic characteristics within and between rhabdoid tumors of the liver, soft tissues, and CNS. In the CNS, rhabdoid tumors may be pure rhabdoid tumors or a variant that has been designated atypical teratoid tumor (AT/RT). Genetic Heterogeneity of Rhabdoid Tumor Predisposition Syndrome See also RTPS2 (613325), caused by germline mutation in the SMARCA4 gene (603254) on chromosome 19p13. [from OMIM]

Schwannomatosis is characterized by a predisposition to develop multiple schwannomas and, less frequently, meningiomas. Individuals with schwannomatosis most commonly present between the second and fourth decade of life. The most common presenting feature is localized or diffuse pain or asymptomatic mass. Schwannomas most often affect peripheral nerves and spinal nerves. Meningiomas occur in about 5% of individuals with schwannomatosis and have only been reported in individuals with SMARCB1-related schwannomatosis. Malignancy remains a theoretic risk especially in individuals with a SMARCB1 pathogenic variant. [from GeneReviews]