Berlin Breakage syndrome
Overview
Nijmegen breakage syndrome (NBS) (also known as Berlin breakage syndrome and Seemanova syndrome) is a rare syndrome characterised by chromosomal instability, probably as a result of a defect in the Double Holliday junction DNA repair mechanism. The name derives from the Dutch city Nijmegen where the condition was first described.[1] Most people with NBS have West Slavic origins. The largest number of them live in Poland
Symptoms
* Small head * Retarded growth * Immunodeficiency * Increased risk of cancer * Low birth weight
Causes
It is caused by a mutation in the NBS1 gene.
Diagnosis
The diagnosis of Nijmegen breakage syndrome (NBS) is suspected in individuals with the following characteristic findings: * Microcephaly occurs in about 75% of affected individuals at birth, and in the remainder during the first months of life. * Growth retardation is either present at birth or becomes manifest before two years of age. Thereafter, growth rate is appropriate, but individuals remain small for age. * The characteristic facial features — a sloping forehead, receding mandible, prominent nasal root and nose, large ears, and upward slant of the palpebral fissures — become apparent at around three years of age. * Recurrent sinopulmonary infections include pneumonia, bronchitis, otitis media, sinusitis, and mastoiditis. * Malignancies, most commonly B-cell lymphoma, which develops in most individuals before the age of 15 years, occur in approximately 50% of individuals with NBS. * In most individuals, decline in intellectual ability results in mental retardation in the borderline-to-moderate range by age ten years.