Autoszomális recesszív
Caused by loss-of-function changes in both copies of BLM, which encodes a DNA helicase that helps repair and stabilise DNA. Without it, cells show greatly increased exchanges between chromosomes, which causes genomic instability.
Tünetek és jelek
Small size before and after birth, with a narrow face and a red, sun-sensitive rash on the cheeks and nose. Cancers of many types, including leukaemia, lymphoma and colorectal cancer, occur far more often and at younger ages than usual. Reduced immunity with frequent infections, type 2 diabetes, reduced fertility in men and early menopause in women are also common.
Mit változtat a diagnózis
Cancer surveillance tailored to the condition, sun protection and regular screening for diabetes are recommended. Because cells are highly sensitive to DNA damage, exposure to X-rays and other ionising radiation is kept low and chemotherapy doses may need adjusting. Both parents of an affected child are usually carriers, so each further child has a 1 in 4 chance of being affected; genetic counselling and carrier testing of relatives are available.
Vizsgált gének
Más néven
BLM; Bloom-Torre-Machacek syndrome; BLS; BS; BSyn; congenital telangiectatic erythema; congenital telangiectatic erythema syndrome; growth deficiency, sun-sensitive, telangiectatic, hypo and hyperpigmented skin, predisposition to malignancy and chromosomal instability; MGRISCE1
