The genetic abnormality in Bloom syndrome causes
problems with DNA repair
, resulting in a high number of chromosome breaks and rearrangements. The abnormal DNA repair is responsible for the increased risk for cancer.
How a genetic syndrome can lead to a predisposition to cancer?
Many family cancer syndromes are caused by
inherited mutations in tumor suppressor genes
. These are genes that normally keep cells under control by slowing down how often they divide (to make new cells), repairing DNA mistakes, or telling cells to die at the right time.
What Chromosome does Bloom syndrome affect?
The gene for Bloom syndrome, BLM, is located on
chromosome 15
(gene locus is band 15q26. 1). Mutations in this gene cause errors in the copying process during DNA replication and result in a higher number of chromosome breakages and rearrangements/sister chromatid exchanges.
How long can you live with Bloom syndrome?
There are fewer than 200 known surviving cases of Bloom syndrome worldwide. Lifespan is limited;
the average age of death is 27 years
. The most common cause of death is from cancer. A genetic condition that appears only in individuals who have received two copies of an autosomal gene, one copy from each parent.
Why is it called Bloom syndrome?
History of Bloom’s Syndrome. In 1954, Dr. David Bloom, a New York City dermatologist, reported on 3 children with telangiectatic erythema and short stature [Bloom, 1954]. He suggested that this condition represented
a unique human syndrome
.
Is cancer hereditary from parents or grandparents?
Although cancer is common,
only 5-10% of it is hereditary
, meaning an individual has inherited an increased risk for cancer from one of their parents. This inherited risk for cancer is caused by a small change (called a mutation) in a gene, which can be passed from one generation to the next in a family.
What percentage of cancer is genetic?
Inherited genetic mutations play a major role in
about 5 to 10 percent of all cancers
. Researchers have associated mutations in specific genes with more than 50 hereditary cancer syndromes, which are disorders that may predispose individuals to developing certain cancers.
What is Bloom’s syndrome?
Listen to pronunciation. (… SIN-drome) A
rare, inherited disorder marked by shorter than average height
, a narrow face, a red skin rash that occurs on sun-exposed areas of the body, and an increased risk of cancer.
Can Bloom syndrome be prevented?
There is no cure for Bloom syndrome
. Children with Bloom syndrome need nutritional monitoring to ensure maximum growth. People with the disease are advised to stay out of the sun and wear sunscreen to prevent skin lesions, particularly during childhood.
How is Bloom syndrome diagnosed and treated?
Bloom syndrome is
diagnosed based on the symptoms, clinical exam, and confirmed by the results of genetic testing
. Sometimes, cytogenetic testing, a blood test to look at a person’s chromosomes , is done to look for features characteristic of Bloom syndrome.
Is Bloom syndrome more common in males or females?
Bloom syndrome is more common in eastern European Ashkenazi Jews. At least 1 in 100 Ashkenazi Jews is a carrier of the disease. It appears to be
slightly more common in males than females
.
Why do Ashkenazi have genetic diseases?
Researchers think Ashkenazi genetic diseases arise
because of the common ancestry many Jews share
. While people from any ethnic group can develop genetic diseases, Ashkenazi Jews are at higher risk for certain diseases because of specific gene mutations.
How do you test for Bloom syndrome?
The diagnosis of Bloom syndrome (congenital telangiectatic erythema) can be confirmed or excluded by
a laboratory test known as a chromosome study
; blood and skin cells show a characteristic pattern of chromosome breakage and rearrangement.
Can you have an XXY chromosome?
Klinefelter syndrome
is a genetic condition in which a boy is born with an extra X chromosome. Instead of the typical XY chromosomes in men, they have XXY, so this condition is sometimes called XXY syndrome. Men with Klinefelter usually don’t know they have it until they run into problems trying to have a child.
How was Bloom syndrome discovered?
Bloom syndrome (congenital telangiectatic erythema) is a rare autosomal recessive disorder. It was first described in 1954 by
David Bloom in a series of patients with
telangiectatic erythema on the face and dwarfism.
How do you know if you have Li Fraumeni syndrome?
If health care providers or genetic counselors suspect a person has Li-Fraumeni syndrome, diagnostic testing may take place:
A blood sample is collected
. DNA is isolated from the cells in the sample, and the TP53 gene is checked for possible mutations using a variety of methods such as DNA sequencing.
