Bloom syndrome

A disease that causes genomic instability as a consequence of the presence of pathogenic variants in the BLM gene that produces a protein involved in DNA repair and replication.

Bloom syndrome is a disease characterized by high genetic instability, which causes breaks and rearrangements in the chromosomes of those affected. The pathology is caused by the presence of mutations in the BLM gene, which codes for a protein of the helicase family, involved in DNA repair. Its inheritance pattern is autosomal recessive.

The overall prevalence of the disease is unknown, but it is most prevalent in the Jewish or Ashkenazi population, where it is estimated at approximately 1 in 48,000 births. To date, at least 300 cases of Bloom's syndrome have been reported.


The symptomatology that characterizes this disease is diverse: increased incidence of cancer at early ages (due to high genetic instability), short stature, telangiectasia (presence of small dilated blood vessels in skin and mucous membranes), presence of hypo- and hyperpigmented areas in the skin, susceptibility to infections due to deficiency of certain immunoglobulins, hypogonadism and infertility in men and early menopause in women.

Disease management

A cure for the disease is not currently available. Treatment of the pathology depends on the symptoms, including treatment with immunoglobulins for deficiencies, skin protection and/or specific treatments for cancer cases that may occur. The administration of growth hormone has also been proposed as part of the treatment, however, there is some controversy in its use because it has been linked to an increased risk of tumor development in children.

Genes analyzed



Ababou M. Bloom syndrome and the underlying causes of genetic instability. Molecular genetics and metabolism. 2021 May;133(1):35-48.

German, J., Sanz, M. M., Ciocci, S., et al. Syndrome-causing mutations of the BLM gene in persons in the Bloom's Syndrome Registry. Human mutation. 2007 Aug;28(8):743-53.

Haven't you taken a DNA test yet?

Get your genetic test and find out all about yourself.

Starter DNA test

Ancestry, Traits and Wellness

DNA test Advanced DNA test

Health, Ancestry, Traits and Wellness

Summer Sale Only until July 25 on our DNA tests. Use our code SUMMER15