Alt. symbols: NBS | NBS1 | ATV | AT-V2 | AT-V1

Approved name: nibrin
Alt. names: Nijmegen breakage syndrome 1 (nibrin)

Location: 8q21.3: 89924515 - 90003228 (-)
Gene type: protein_coding, 38 transcripts.

Scores: LoFtool: 0.811000 | pLI: 0.00000000 | LOEUF: 1.010

HGNC: 7652

NCBI: 4683, RefSeq: NG_008860.1

Ensembl: ENSG00000104320.15

LRG_158 | Status: public

OMIM: 602667

Expression | ProteinAtlas

The NBN gene encodes the nibrin protein. Nibrin is involved in several critical cellular functions, including the repair of damaged DNA. To this end, nibrin interacts with the proteins encoded by the MRE11A and RAD50 genes, as part of a larger protein complex. Nibrin regulates the activity of this complex by carrying the MRE11A and RAD50 proteins into the cell’s nucleus and guiding them to sites of DNA damage. The proteins work together to mend broken strands of DNA. DNA can be damaged by agents such as toxic chemicals or radiation, and breaks in DNA strands also occur naturally when chromosomes exchange genetic material in preparation for cell division. Repairing DNA prevents cells from accumulating genetic damage that may cause them to die or to divide uncontrollably. The MRE11A/RAD50/NBN complex interacts with the protein produced from the ATM gene, which plays an essential role in recognizing broken strands of DNA and coordinating their repair. The MRE11A/RAD50/NBN complex helps maintain the stability of a cell’s genetic information through its roles in repairing damaged DNA and regulating cell division. Because these functions are critical for preventing the formation of cancerous tumors, nibrin is described as a tumor suppressor.

Biallelic mutations in the gene cause autosomal recessive Nijmegen breakage syndrome (NBS) [MIM:251260]. The most common mutation is the c.657del5 (p.K219NfsX16), which was initially identified in homozygosity in 58 patients and in one heterozygous carrier (Varon et al., 1998, Matsuura et al., 1998). In addition, the homozygous mutation p.I171V was reported to cause aplastic anemia (Shimada et al. 2004). Heterozygous mutations may also predispose to the development of various types of cancers, i ncluding cancers of breast, colon, prostate and hematological cancers, such as acute lymphoblastic leukemia [MIM:613065]. Moreover, 13 heterozygous NBN frameshift mutation carriers from three unrelated NBS families (c.657del5, c.835del4 and c.900del25) were shown to be affected by chromosomal breakages and rearrangements in peripheral blood lymphocytes (Tanzarella et al., 2003). [Load More]