Sunday, 27 July 2003
Last Updated Tuesday, 23 November 2004
What
Bloom syndrome is a
cancer-prone
genetic disorder that is considered to be a “
chromosome breakage” disease. Chromosomes are structures in each of the
cells of our bodies that contain our genetic material, which makes us who we are. Individuals with Bloom syndrome have chromosomes that are more susceptible to breaking and rearranging which alters the normal genetic code.
Who
Bloom syndrome is most common in Ashkenazi Jews. It is an
autosomal recessive disease, meaning an individual must inherit two copies of the BLM
gene (one from the father and one from the mother) in order to get the disease. It has been found that approximately 1 of every 100 Ashkenazi Jews is a
carrier of the BLM
gene. If both parents carry one copy of the BLM
gene, there is a 25% chance that each of their children will inherit the disease. The onset of Bloom syndrome occurs in the first few months of life, and males are slightly more susceptible to the disease than females, the male-to-female ratio is 1.3 to 1.
Signs and Symptoms
Bloom syndrome is primarily characterized by red spots on the skin due to dilated small blood vessels,
sensitivity to sunlight, growth deficiency, variable degrees of deficiency of the
immune response causing the individual to be more
susceptible to illnesses and infections and an increased susceptibility to
cancer. Other signs and symptoms may occur in individuals with Bloom syndrome.
unusual facial features: large protruding ears, long narrow face with prominent nose, small lower jaw, defective teeth formation, high pitched voice
skeletal abnormalities: short stature, long arms and short legs in proportion to body length, disproportionately large hands and feet, webbed hands or feet, increased number of fingers or toes, crooked fingers,
developmental delay, often mental retardation
Possible Causes
Bloom syndrome is caused by abnormal changes in the BLM
gene located on
chromosome 15. Men are usually infertile and women have reduced fertility.
Diagnosis
Testing for
chromosome instability and immunoglobulin levels help in the diagnosis of Bloom syndrome.
Treatment
There is no specific treatment for Bloom syndrome. Individuals with this disease are advised to stay out of the sun and use sunscreen to prevent skin lesions. They are also advised to make an effort to avoid exposure to infections. Surgical correction of the hands and feet is available. Special educational programs are located in infant programs and schools. Further care will be needed if
cancer develops.
Prognosis
There is an increased risk of premature death of individuals in their 20’s and 30’s who have Bloom syndrome. This is due to the increased risk of
cancer. Patients who survive beyond the age of 22 will usually develop tumors in their mid 30’s, but these tumors are usually sensitive to chemotherapy and radiotherapy. The resistance to infections improves with age, and so does the photosensitivity and redness of the skin.
Connect with other parents
In the spirit of community and support, Madisons Foundation offers the unique service of connecting parents of children with rare diseases. If you would like to be connected to other parents of children with this disease,
please fill out this brief form.
Weblinks
MazorNet
Nicely written information about the disease.
Family Village
A website with good educational information and links to support groups and other sites.
Magic Foundation
A foundation dedicated to helping families and children whose growth is affected by a medical problem.
National Foundation of Jewish genetic Diseases, Mount Sinai Medical Center
dedicated to researching genetic diseases affecting predominantly Ashkenazi Jews.
Google Search for Bloom Syndrome
References and Sources
Behrman: Nelson Textbook of Pediatrics, 16th ed., (2002). home.mdconsult.com
Emedicine: Bloom Syndrome (
congenital Telangiectatic Erythema) www.emedicine.com/DERM/topic54.htm
Griffiths 5 Minute Clinical Consult, 11th ed., (2001) online.statref.com
Rudolph’s Pediatrics- 21st ed. (2002). www.online.statref.com