Individuals with Bloom syndrome have short stature, sun-sensitive facial skin lesions, an increased susceptibility to infections and respiratory illness, and an increased predisposition to certain cancers and leukemia. Men with Bloom syndrome are usually infertile, and fertility appears to be reduced in women. Some individuals with Bloom syndrome also have mental retardation. These individuals usually die at an early age, but some have survived until their forties.

Bloom syndrome is a rare disease that is most common in the Ashkenazi Jewish population. One out of every 100 Ashkenazi Jews is a carrier of this disease, which is caused by a change in a gene located on chromosome 15.

Bloom syndrome is considered a "chromosome breakage" disease. This means that affected individuals have an increased rate of breakage and rearrangements along their chromosomes. Chromosomes are the structures in each of the cells in our body that contain our genes. Genes make up who we are and guide the development of the body.

Early diagnosis of this disease can be helpful in monitoring and treating the manifestations of Bloom syndrome. Affected individuals should be more attentive in their surveillance for cancer and should also decrease exposure to sunlight and X-rays, which may cause damage to their chromosomes.