Genomic coordinate 8:89,933,331
Here I present: “Nijmegen Chromosome Breakage Syndrome”, Victor McKusick, Mendelian Inheritance in Man’, 1966. 奈梅亨斷裂綜合。icd10=Q87.8
INTRODUCTION.
Nijmegen breakage syndrome (NBS) was first described in 1981 in Dutch patients, however, the majority of NBS patients live in Poland and the Czech republic and the Dutch patients may have had Bohemian ancesters who emigrated to Holland in the first half of the 17th century after the 30 Years War.
Nijmegen breakage syndrome is an autosomal recessive congenital disorder causing chromosomal instability, probably as a result of a defect in the double-Holliday-junction DNA-repair mechanism and/or the synthesis-dependent strand-annealing mechanism for repairing double strand breaks in DNA.
Patients with NBS have a characteristic facial appearance with a combination of receding forehead, receding mandible and prominent midface. In addition, most patients have epicanthal folds, large ears, and sparse hair. The facial features are perhaps even more striking since patients with NBS are also microcephalic, as illustrated by the head circumference. Mental retardation is generally mild, with most patients having an IQ within the normal range.
Nijmegen breakage syndrome (NBS) and the phenotypically indistinguishable Berlin breakage syndrome are autosomal recessive chromosomal instability syndromes characterized by microcephaly, growth retardation, immunodeficiency, and predisposition to cancer.
There is evidence that Nijmegen breakage syndrome is caused by homozygous or compound heterozygous mutation in the nibrin (NBN) gene on cytogenetic location 8q21.3 and genomic coordinates 8:89,933,331-89,984,667. The screenshot of the NBN gene 51,337 bp (base pairs) of DNA sequence length is shown BELOW. Nine (9) other genes besides NBN in the 8q21.3 cytogenetic location are listed BENEATH.
| Coordinate | Symbol | Genomic Name |
| 8:87,870,747 | DCAF4L2 | DDB1- and CUL4-associated factor 4-like 2 |
| 8:88,032,011 | MMP16 | Matrix metalloproteinase 16 |
| 8:89,757,816 | RIPK2 | Receptor-interacting serine/threonine kinase 2 |
| 8:89,901,868 | OSGIN2 | Oxidative stress-induced growth inhibitor 2 |
| 8:89,933,331 | NBN | Nibrin |
| 8:90,001,477 | DECR1 | 2,4-dienoyl CoA reductase |
| 8:90,058,608 | CALB1 | Calbindin 1, 28kD |
| 8:90,621,995 | TMEM64 | Transmembrane protein 64 |
| 8:90,993,802 | TMEM55A | Transmembrane protein 55A |
| 8:91,070,344 | OTUD6B | OTU domain-containing protein 6B |
