Скачать или смотреть Bloom syndrome; inherited disorder that affects growth, immune function, and increases cancer risk

Bloom syndrome is a rare inherited disorder characterized by genomic instability, growth deficiency, and increased cancer risk. It belongs to the group of chromosome breakage syndromes.

Key Features
Growth deficiency: Short stature, low birth weight, poor postnatal growth.

Skin findings:

Sun‑sensitive rash (especially on face).

Telangiectasias (dilated blood vessels).

Café‑au‑lait spots.

Immune deficiency: Recurrent infections due to impaired immune function.

Cancer predisposition: Very high risk of multiple cancers (leukemia, lymphoma, solid tumors) at a young age.

Other features: Male infertility, female subfertility, learning difficulties in some cases.

Genetics
Inheritance: Autosomal recessive.

Gene involved: Mutations in the BLM gene on chromosome 15.

Function of BLM: Encodes a DNA helicase involved in DNA repair and replication.

Pathogenesis: Defective DNA repair → chromosomal instability → increased sister chromatid exchanges (diagnostic hallmark).

Diagnosis
Clinical features: Growth retardation, sun‑sensitive rash, cancer history.

Laboratory:

Cytogenetic testing shows excessive sister chromatid exchange.

Genetic testing confirms BLM mutation.

Management
Supportive care:

Sun protection for skin lesions.

Infection prevention and treatment.

Cancer surveillance: Regular screening due to high risk.

Genetic counseling: Important for affected families.

No curative therapy currently; management is preventive and supportive

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