Nijmegen breakage syndrome (NBS), causes people to get cancer early on and often have frequent lung and sinus infections.
Babies with NBS usually have a small head size and grow more slowly than other kids their age, making them smaller overall. As they grow, they develop distinct features like a sloping forehead, small chin, big ears, and a prominent nose. In a study, 35% of 70 people with NBS got cancer, mostly a type called B-cell lymphoma, between ages 1 and 34. Since people with NBS can’t handle the high doses of radiation used in cancer treatment, they need different methods like chemotherapy. Those with NBS have a weaker immune system, leading to lots of infections in the lungs, ears, sinuses, and urinary tract. In some cases, severe pneumonia or bronchitis could be life-threatening. While their intelligence seems normal in early childhood, it often declines, reaching mild-to-moderate intellectual disability around age 10. There’s no cure for the main issue in NBS, but specific symptoms can be managed.
NBS is caused by pathogenic (disease-causing) variants in the NBN gene and exhibits autosomal recessive inheritance. This means that both parents must be carriers to have a 25% chance to have a child with the condition. The risk of being a carrier is based on a person’s ancestry or ethnic background. For example, individuals of Ashkenazi Jewish descent have a 1 in 427 chance to be a carrier.
Carriers may be at higher risk for developing certain types of cancer. If you are found to be a carrier, a genetic counselor can talk to you in more detail about this risk and what it means.
Other names for this condition are ataxia-telangiectasia variant 1, Berlin breakage syndrome, and Seemanova syndrome.