SWI/SNF related, matrix associated, actin dependent regulator of chromatin, subfamily b, member 1
385 amino acids; about 44 kDa
The product of the gene binds and activates human immunodeficiency virus integrase; it is a member of the SWI/SNF complex, thought to facilitate the transcriptional activation of inducible genes through the remodelling of the chromatin; SMARCB1 could be involved in the chromatin organization associated with the nuclear matrix attachment; it could also have a role in the cell cycle control, through binding to P105-Rb
Various types of SMARCB1 somatic mutations have been described in various tumor types, including soft tissue, CNS, bone and skin tumors. No specific mutation hot spots have been reported.
Genetic alterations in SMARCB1 are a cause of rhabdoid tumor (RDT). RDT are a highly malignant group of neoplasms that usually occur in early childhood.
Defects in SMARCB1 are a cause of schwannomatosis. Schwannomas are benign tumors of the peripheral nerve sheath that usually occur singly in otherwise normal individuals. Clinical report suggests that schwannomatosis is a clinical entity distinct from other forms of neurofibromatosis, notably the NF1-associated form.
The role of SMARCB1/INI1 in development of rhabdoid tumor. Roberts CW, Biegel JA. Cancer Biol Ther. 2009 Mar;8(5):412-6.