Bloom's Syndrome carried by 1 in 100 Ashkenazi Jews.
Bloom syndrome is a rare inherited illness characterized by a high frequency of breaks and rearrangements in an affected person's chromosomes. Bloom syndrome is a very rare disorder in most populations. It is more common in people of Central and Eastern European (Ashkenazi) Jewish background, among whom 1 in 48,000 are affected. Approximately one third of people with Bloom syndrome are of Ashkenazi Jewish descent. Bloom's Syndrome is caused by a genetic mutation on chromosome 15. This causes a change in the enzyme known as DNA ligase.
The vital function of which is to link the components that make the DNA strand - without it, nothing could live. In sufferers, the gene mutations cause the enzyme to be defective, but not completely ineffective (or else the person would never have developed from zygote status!). DNA repair mechanisms operate constantly in higher organisms because DNA is continually damaged by radiation (such as from sunlight) and chemicals in the environment. Men with Bloom syndrome are infertile and women have reduced fertility and experience menopause at an earlier age. Overall, Bloom syndrome confers a 150-300 times increased risk of cancer.
As compared to the general population, causing life expectancy to be shortened. Affected individuals develop the full range of cancers found in the general population, but the cancers arise unusually early in life. Bloom syndrome has no specific treatment; however, avoiding sun exposure and using sunscreens can help prevent some of the cutaneous changes associated with photosensitivity. Respiratory infections require prompt antibiotic treatment. Although growth hormone therapy has been attempted to increase height in children with Bloom’s syndrome, it does not appear to be effective.
