Clinical Guidance

No genotype-phenotype correlations have been identified.

Source: GeneReviews — "Bloom Syndrome"

Diagnostic Criteria

Suggestive Findings

Bloom syndrome (BSyn) should be suspected in an individual with any of the following clinical or cytogenetic findings.

Clinical findings

• Prenatal-onset growth deficiency that usually affects linear growth, weight gain, and head circumference and that persists into infancy, childhood, and adulthood

• Moderate-to-severe growth deficiency and a sun-sensitive, erythematous rash that commonly involves the face and appears in a butterfly distribution

• Moderate-to-severe growth deficiency and a diagnosis of cancer, usually occurring at an earlier age than in the general population

Cytogenetic findings. Increased numbers of sister-chromatid exchanges (SCEs)

Establishing the Diagnosis

The diagnosis of BSyn is established in a proband with biallelic pathogenic (or likely pathogenic) varia...

Source: GeneReviews — "Bloom Syndrome"

Differential Diagnosis

Genetic disorders of interest in the differential diagnosis of Bloom syndrome are listed in . Table 3. Genetic Disorders of Interest in the Differential Diagnosis of Bloom Syndrome

Management Guidelines

Health supervision recommendations that address diagnosis, treatment, and surveillance for complications in persons with Bloom syndrome (BSyn) have been published . Evaluations Following Initial Diagnosis To establish the extent of disease and needs in an individual diagnosed with BSyn, in addition to the routine medical history, family history, and physical examination, the evaluations summarized (if not performed as part of the evaluation that led to the diagnosis) are recommended. Table 4. Bloom Syndrome: Recommended Evaluations Following Initial Diagnosis

Source: GeneReviews — "Bloom Syndrome"

Clinical Guidance

Sun exposure to the face and other exposed skin, particularly in infancy and early childhood, should be avoided. Exposure to ionizing radiation should be minimized. People with BSyn should avoid unnecessary radiographs and CT scans; MRI and ultrasound are preferred imaging modalities when able to be used. Chemotherapy can have significant side effects and toxicity (including secondary malignancies). Dose reductions and shortened courses of treatment are generally utilized for individuals with BSyn. Alkylating agents and radiation therapy are considered high risk and are avoided when possible in those with BSyn.

Source: GeneReviews — "Bloom Syndrome"

Therapies Under Investigation

Search ClinicalTrials.gov in the US and EU Clinical Trials Register in Europe for information on clinical studies for a wide range of diseases and conditions. Note: There may not be clinical trials for this disorder.

Source: GeneReviews — "Bloom Syndrome"

Surveillance Guidelines

Health supervision recommendations for surveillance in persons with BSyn have been published . 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. Table 6. Bloom Syndrome: Recommended Surveillance

Source: GeneReviews — "Bloom Syndrome"