DNA helicases function in DNA replication and DNA repair. BLM very likely functions in DNA replication, as cells from persons with Bloom syndrome exhibit multiple defects in DNA replication, and they are sensitive to agents that obstruct DNA replication.The BLM helicase is a member of a protein complex with topoisomerase III alpha, RMI1 and RMI2, also known as BTRR, Bloom Syndrome complex or the dissolvasome. Disruption of the proper assembly of the Bloom Syndrome complex leads to genome stability, genetic dependence on cellular nucleases GEN1 and MUS81, and loss of normal cell growth. Bloom-like phenotypes have been associated with mutations in topoisomerase III alpha, RMI1 and RMI2 genes. Relationship to cancer and aging
As noted above, there is greatly elevated rate of mutation in Bloom syndrome and the genomic instability is associated with a high risk of cancer in affected individuals. The cancer predisposition is characterized by 1) broad spectrum, including leukemias, lymphomas, and carcinomas, 2) early age of onset relative to the same cancer in the general population, and 3) multiplicity, that is, synchronous or metachronous cancers. There is at least one person with Bloom syndrome who had five independent primary cancers. Persons with Bloom syndrome may develop cancer at any age. The average age of cancer diagnoses in the cohort is approximately 26 years old. Pathophysiology
When a cell prepares to divide to form two cells, the chromosomes are duplicated so that each new cell will get a complete set of chromosomes. The duplication process is called DNA replication.
Xerotic eczema  is a form of eczema that is characterized by changes that occur when skin becomes abnormally dry, red, itchy, and cracked. It tends to occur more often during the winter and in dry conditions. Xerotic eczema is common in elderly people, though it is not uncommon for people in their 20s. It can appear in red, bumpy, pimple-like irritations. Treatment
The first method that should be taken when treating xerotic eczema is attempting to re-hydrate the dry skin using a humidifier and bathing/showering less frequently. Mild and moisturizing soaps should be used to prevent further irritation. Scratching the affected area should be avoided. Applying moisturizing lotion or anti-itch ointment frequently should help in reducing dryness. If the re-hydration process does not alleviate the symptoms, moisturizers such as Lac-Hydrin 5% or 12% moisturizer containing urea can be used; furthermore, if the skin becomes inflamed or cracked, mid- to high-potency corticosteroids can be used.A study published in 2005 found positive results from soaking the affected area in water for twenty minutes and then applying mid- to high-strength corticosteroid ointment. See also
Skin lesion


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