The treatment of Bloom syndrome is symptomatic and supportive. Health supervision recommendations that address diagnosis, treatment and surveillance for complications in persons with Bloom syndrome have been published [Cunniff et al. 2018].
Both to prevent skin cancer and the typical red rash that is common in BSyn, persons with Bloom syndrome should limit contact with direct sunlight by seeking shade, especially between 10 a.m. and 4 p.m. Health recommendations also suggest covering exposed skin with clothing, including a broad-brimmed hat and UV-blocking sunglasses, and applying a broad-spectrum sunscreen with SPF of 30 twice daily, or every 2-3 hours if outdoors. Annual evaluation by a dermatologist is also advised.
Family members, friends and teachers are encouraged to relate to persons with BSyn appropriately for their chronologic age rather than the younger age suggested by their unusually small size. Nonetheless, infants, toddlers, and preschool-age children with BSyn should have close developmental monitoring and referral for early intervention services. If developmental delays are present, physical, occupational, and speech therapy can help. School performance should be assessed regularly, and parents should be aware of educational support available.
Growth hormone administration to children with BSyn has not consistently increased growth rate in most persons, but some have experienced improved linear growth. Use of growth hormone has been approached cautiously in this population, because of concerns regarding an increased risk to develop tumors as a result of their treatment. If growth hormone is prescribed, the growth response and serum IGF-1 and IGFBP-3 levels should be closely monitored, and unless there is an increase in growth velocity while under treatment, it should be discontinued.
Because of an increased incidence of hypothyroidism among the BSyn population, serum TSH with reflex to T4 should be measured annually beginning at 10 years. Additionally, recent health supervision guidelines suggest screening and family education on the signs and symptoms of hypothyroidism, including fatigue, constipation, cold sensitivity, and weight gain.
Until additional information is available regarding treatment of problematic feeding behaviors and gastrointestinal symptoms, standard treatment for these concerns is recommended. This may include consultation with a gastroenterologist or feeding specialist, use of high calorie diets, institution of reflux precautions and use of anti-reflux medications. While supplemental feeding may result in increased fat deposition, it does not necessarily result in improved linear growth. Because abnormalities have been identified in the lipid profile of persons with BSyn, caution should be exercised in the use of high fat and/or high cholesterol diets. A lipid profile to detect dyslipidemia is recommended annually beginning at 10 years; for those with dyslipidemia, dietary treatment according to standard protocols is recommended.
Diabetes mellitus is also prevalent among the BSyn population, so fasting blood glucose and hemoglobin A1C should be measured annually beginning at 10 years, and patients, their families, and their doctors should be alert for signs and symptoms such as increased thirst, increased urination, and weight loss. Treatment of diabetes mellitus in BSyn is the same as in other persons.
For those with defects in humoral immunity, weekly subcutaneous or monthly intravenous infusions of gamma globulin may be beneficial. Cough assist devices, vibration vests, and daily nasal lavage can be used to for mucociliary clearance for bronchiectasis. If an individual with BSyn experiences recurrent, severe, or opportunistic infection, then immunodeficiency screening, including immunoglobulin level, antibody responses to vaccines, and quantitative B and T lymphocyte measurements, are recommended.
Physicians must be conscientious in watching for indications of cancer, especially with patients who reach adulthood. A timeline for when to begin the suggested screenings and how often they should recur has been published [Cunniff et al. 2018]. It should be recognized however, that these recommendations are based on limited data from the Bloom Syndrome Registry and on expert opinion. There are currently no clinical trials or case control studies that address outcomes in people with BSyn. Because of the unusually high risk for early development of cancer, much of the health supervision effort is directed to early detection and treatment.
For pediatric patients, recent health supervision guidelines suggest screening for Wilms tumor by performing an abdominal ultrasound every 3 months from the age of diagnosis until 8 years, in addition to screening for signs and symptoms such as hematuria and a painless abdominal mass. Surveillance for hematological cancers largely depends on awareness of sign/symptoms, including unintentional weight loss and fatigue; additionally, pallor, abnormal bleeding, and petechiae when surveilling for leukemia and enlarged lymph nodes, unexplained fevers, and drenching night sweats for lymphoma. Screening for colorectal cancer begins at 10-12 years, with an annual colonoscopy and fecal immunochemical testing (FIT) every 6 months. In affected females over the age of 18, a breast MRI to detect breast cancer is recommended annually. The most recent guidelines also recommend a whole-body MRI every 1-2 years beginning at age 12 or 13 to detect other solid tumors or lymphomas.
When treating cancer, the hypersensitivity of persons with BSyn to both DNA-damaging chemicals and ionizing radiation ordinarily necessitates modification of standard cancer treatment regimens, which usually includes a reduction of both dosage and duration. Individuals with BSyn have usually tolerated doses at or below 50% of the standard chemotherapy dosage, with no clear evidence that this has resulted in poorer outcomes. However, full weight-based dosing may be appropriate for some chemotherapeutic drugs such as steroids and tyrosine kinase inhibitors. Absence of information as to the ideal dosages makes such treatment particularly challenging to the physician; nevertheless, the fact that the cancers themselves often appear unusually responsive to the treatment justifies the special effort. If HSCT is being contemplated, nonmyeloablative transplantation is likely to be tolerated more readily than other regimens. Additionally, the required ablative therapy prior to BMT often may require modification of standard protocols because of the hypersensitivity of persons with BSyn to DNA-damaging agents.
Because infertility is a common issue, men with BSyn can undergo semen analysis to assess for abnormalities in the quantity and motility of sperm (azoospermia, oligospermia, or asthenospermia). Women with BSyn should be aware of signs of early menopause and may also consider oocyte (egg) freezing (cryopreservation). Additionally, assisted reproductive technology (ART) may be beneficial if natural conception is not possible, but there are currently no reports of ART in this population. Those who wish to conceive should consider consulting with a fertility specialist.
Genetic counseling is recommended for people with Bloom syndrome and their families. Preimplantation and prenatal diagnosis are possible if the BLM mutations have been identified in the at-risk couple.