Berlin Breakage Syndrome
Berlin Breakage Syndrome Causes
It is caused by a mutation in the gene NBS1. Berlin breakage syndrome is a disease with an autosomal recessive pattern of inheritance. Interfamily matings have been reported. The gene responsible for NBS, designated as NBS1, is located on the 8q21 band. This NBS1 gene is made up of 16 exons and spans a DNA region of more than 50 kilobases. All disease-causing mutations identified to this day have been found within exons 6-10 in the NBS1 gene and which led to the production of a shortened protein.
Berlin Breakage Syndrome Definition
Berlin breakage syndrome, also known as Nijmegen breakage syndrome (NBS) and Seemanova syndrome, is a rare syndrome that is characterized by chromosomal instability, maybe as a result of a defect in the Double Holliday junction DNA repair mechanism. It is a very rare syndrome characterized mainly by a small head, lowered immunity and heightened risk of cancer. The features of this condition are basically indistinguishable from the Nigmegen Breakage syndrome. The name comes from the Dutch city Nijmegen where the condition was first discovered. Most people with NBS originate from West Slavic regions. The largest number of them is Polish.
Berlin Breakage Syndrome Prevalence
The entire number of patients identified worldwide is increasing systematically, probably due to the fact that physicians are becoming more aware of this disorder. The largest groups of patients as of April 2005 were diagnosed in Poland with 97, the Czech Republic and Slovakia with 37, Germany with 21, and Ukraine with 14. NBS has also been reported in the following countries: Italy, France, Argentina, Great Britain, The Netherlands, Yugoslavia, Spain, Bosnia, Croatia, Turkey, Russia, Morocco, Chile, and New Zealand.
Berlin Breakage Syndrome Symptoms and Signs
People affected with Berlin breakage syndrome display small heads, have retarded growth and immunodeficiency, and have an increased risk of cancer. Other physical characteristics of patients are receding or small jaws, beaked or large noses, deep upper lip groove, low frontal hairline, may have sparse scalp hair, upslanted space between the eyelids, and are short in stature. Patients may also suffer from chronic inflammatory lung disease and humoral immune deficiency. They may also display wasted muscles and underdeveloped thymus. The Berlin breakage syndrome is characterized by microcephaly, or small heads. Patients have a distinct facial appearance, short height, problems with their immune system, sensitivity to radiation, and a strong tendency to lymphoid malignancy. Less common symptoms of the disease are leukemia, sensitivity to light, respiratory distress, and a caf?-au-lait spot. They may also be viselike and possess cleft lips and palates.