Bloom Syndrome
Bloom Syndrome Causes
The condition is inherited with an autosomal recessive pattern of inheritance. Its gene locus is called band 15q26.1. Cytogenetic findings in a Bloom syndrome patient with acute myeloid leukemia of the French-American-British subtype M1 showed an occurrence of total or partial loss of chromosome 7. Mutation of the DNA ligase I gene may also account for the primary metabolic defect in Bloom syndrome, not because of a reduction in the number of protein molecules or to inhibitory substances, but rather to the ATP-binding and hydrolytic activity of the enzyme. DNA ligase I and DNA polymerase alpha are enzymes that function during DNA replication; DNA ligase II and DNA polymerase-beta work during DNA repair.
Bloom Syndrome Definition
Bloom syndrome is a rare autosomal recessive disorder characterized by telangiectases and photosensitivity, deficiency in growth of prenatal onset, variable degrees of immunodeficiency, and increased susceptibility to neoplasms of many sites and types. The dermatologist David Bloom first described the syndrome in 1954.
Bloom Syndrome Symptoms and Signs
People with Bloom syndrome are much shorter and smaller than average, and often have a high-pitched voice and characteristic facial features including a long, narrow face; small lower jaw; and prominent nose and ears. They tend to develop pigmentation changes and dilated blood vessels in the skin, particularly due to sun exposure. These changes often appear as a butterfly-shaped patch of reddened skin on the patient's face. The skin changes may also affect the limbs. Other features of the disorder may include mental retardation, learning disabilities, diabetes, chronic lung problems, and immune deficiency that leads to recurrent pneumonia and ear infections. Men with Bloom syndrome generally do not produce sperm and, as a result, are unable to father children. Women with the disorder generally experience menopause earlier than most.
Bloom Syndrome Treatment
There are no treatments for the underlying cause of Bloom's syndrome, and therefore medical intervention is primarily preventative. Adults with Bloom's syndrome should be more cautious and atentive than others in their surveillance for cancer. It is recommended that people afflicted by this disease maintain a close contact with a physician familiar with Bloom's. This way, with the doctor's assistance, pay attention to in case of an emergence of symptoms that may signal or show a treatable pre-cancerous condition. Bloom syndrome has no specific treatment for it; however, avoiding sun exposure and using sunscreens can help individuals avoid some of the cutaneous changes associated with photosensitivity. Efforts to minimize exposure to other known environmental mutagens are also recommended.