Bloom syndrome

Bloom syndrome is a rare autosomal recessive genetic disorder marked by short stature, a predisposition to cancer and genomic instability. It is caused by mutations in the BLM gene, a member of the RecQ DNA helicase family; mutations in two other family members, WRN and RECQL4, are linked to Werner syndrome and Rothmund-Thomson syndrome. Cells from a person with Bloom syndrome show striking genomic instability, including excessive crossovers between homologous chromosomes and sister chromatid exchanges. The New York dermatologist Dr. David Bloom discovered and first described the condition in 1954, and older literature sometimes calls it Bloom-Torre-Machacek syndrome. It belongs to a wider class of disorders characterized by chromosomal or genomic instability together with cancer predisposition.