The rash commonly also affects the backs of the hands and neck, and it can develop on any other sun-exposed areas of the skin. The rash is variably expressed, being present in a majority but not all persons with Bloom syndrome, and it is on average less severe in females than in males. Moreover, the sun sensitivity can resolve in adulthood. There are other dermatologic changes, including hypo-pigmented and hyper-pigmented areas, cafe-au-lait spots, and telangiectasias, which can appear on the face and on the ocular surface.There is a characteristic facial appearance that includes a long, narrow face; prominent nose, cheeks, and ears; and micrognathism or undersized jaw. The voice is high-pitched and squeaky. There are a variety of other features that are commonly associated with Bloom syndrome. There is a moderate immune deficiency, characterized by deficiency in certain immunoglobulin classes and a generalized proliferative defect of B and T cells. The immune deficiency is thought to be the cause of recurrent pneumonia and middle ear infections in persons with the syndrome. Infants can exhibit frequent gastrointestinal upsets, with reflux, vomiting, and diarrhea, and there is a remarkable lack in interest in food. There are endocrine disturbances, particularly abnormalities of carbohydrate metabolism, insulin resistance and susceptibility to type 2 diabetes, dyslipidemia, and compensated hypothyroidism. Persons with Bloom syndrome exhibit a paucity of subcutaneous fat. There is reduced fertility, characterized by a failure in males to produce sperm (azoospermia) and premature cessation of menses (premature menopause) in females.
Treatment
Bloom syndrome has no specific treatment; however, avoiding sun exposure and using sunscreens can help prevent some of the cutaneous changes associated with photo-sensitivity. Efforts to minimize exposure to other known environmental mutagens are also advisable. Epidemiology
Bloom syndrome is an extremely rare disorder in most populations and the frequency of the disease has not been measured in most populations. However, the disorder is relatively more common amongst people of Central and Eastern European Ashkenazi Jewish background. Approximately 1 in 48,000 Ashkenazi Jews are affected by Bloom syndrome, who account for about one-third of affected individuals worldwide. Blooms Syndrome Registry
The Blooms Syndrome Registry lists 265 individuals reported to have this rare disorder (as of 2009), collected from the time it was first recognized in 1954. The registry was developed as a surveillance mechanism to observe the effects of cancer in the patients, which has shown 122 individuals have been diagnosed with cancer. It also acts as a report to show current findings and data on all aspects of the disorder. See also
Accelerated aging disease
Bloom syndrome (gene)
DNA repair
Progeria
Tumor M2-PK

References
Flanagan M, Cunniff CM (February 14, 2019) [March 22, 2006]. Adam MP, Ardinger HH, Pagon RA,  et al. (eds.). "Bloom syndrome". GeneReviews. Seattle (WA): University of Washington. PMID 20301572. Retrieved July 14, 2019. Further reading
Adam, M. P.; Mirzaa, G. M.; Pagon, R. A.; Wallace, S. E.; Bean LJH; Gripp, K. W.; Amemiya, A. (1993). Margaret P Adam; Holly H Ardinger; Roberta A Pagon; Stephanie E Wallace;  et al. (eds.). GeneReviews. Seattle (WA): University of Washington. ISSN 2372-0697.