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BLOOM SYNDROME

DEFINITION:

A chromosomal breakage disorder affecting multiple systems characterized primarily by telangiectatic erythema and short stature.

EPIDEMIOLOGY:

incidence: ?
age of onset:
- first year (telangiectasia)
risk factors:
- familial - autosomal recessive
  - chrom. #: ?12
  - gene: ?
- Ashkenazi Jews
- M > F (4:3)

PATHOGENESIS:

1. Background

considered to be a "chromosomal breakage syndrome"
- one of at least 4 disorders associated with a high fre-quency of chromosomal breaks and rearrangements and with an increased risk of lymphoreticular (leukemia and lymphoma) and other malignancies
- other syndromes:
  - Ataxia-Telangiectasia
  - Fanconi Anemia
  - Xeroderma Pigmentosum

2. Genetic Defect

genetic defect -> decreased activity of DNA ligase I -> genomic instability -> multisystem anomalies

3. Chromosomal Abnormalities

chromosomal breaks, gaps, and rearrangements
exchange of chromatid segments between homologous chromosomes (i.e., No. 6-12 and No. 19-20 groups) results in:
- quadriradial figures - during metaphase
- harlequin effect

CLINICAL FEATURES:

1. Cutaneous Manifestations

1. Telangiectatic Erythema

appears on face in a butterfly distribution during the first year of life after exposure to sunlight
improves after childhood
may also appear on hands and forearms and occasionally ears and neck
skin involvement milder in females

2. Others

acanthosis nigricans - ichthyosis
bullous eruption on lips - pilonidal cysts
cafe-au-lait spots - sacral dimples
hypertrichosis

2. Craniofacial Manifestations

microcephaly with dolichocephaly
malar hypoplasia +/- nasal prominence
small mandible
prominent ears with recurrent otitis media
defective dentation
high-pitched voice

3. Musculoskeletal Manifestations

1. Short Stature

may present prenatally as low birth weight
associated with feeding problems
may lead to dwarfism
shortened lower extremities

2. Others

club feet
syndactyly, polydactyly, clinodactyly of 5th finger

4. Other Manifestations

1. Neurological

normal intelligence

2. Immune

recurrent respiratory tract and gastrointestinal infections

3. Endocrine

hypospadias, cryptorchidism, azoospermia
diabetes mellitus

4. Neoplasms (25% of patients)

1. Lymphoreticular Tumors

lymphomas - Non-Hodgkin's Diseases
leukemias - acute nonlymphocytic leukemia
tend to occur before age 25

2. Carcinomas

tongue, larynx, lung, esophagus, colon, skin, breast, cervix
tend to occur after 20 years of age

3. Others

Wilms' Tumor

INVESTIGATIONS:

1. Serum

deficiency of IgM and IgA

MANAGEMENT:

1. Supportive

no treatment available
surveillance for and treatment of all infections and neoplasms

Pediatric Database - BLOOM SYNDROME

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