Deletion of the long arm of chromosome 5 (5q-) as a secondary event in the course of refractory anemia.
A 54-year-old chemical plant worker developed mild pancytopenia, with normal bone marrow morphology. Normal bone marrow cytogenetics were documented. The patient developed worsening anemia 5 years into his course. The bone marrow morphology remained normal, but four of 30 bone marrow metaphases examined showed deletion of the long arm of chromosome #5. Eight years into his course, the patient developed severe thrombocytopenia, and his bone marrow became hypercellular, with dysplastic changes. Deletion of the long arm of chromosome #5 was seen in all of 21 bone marrow metaphases examined. There had been no new exposure to potential mutagens during the course of the patient's illness. The occasional documentation of the late appearance of cytogenetic abnormalities during the course of clonal hematopoietic disorders implies that, in some cases at least, chromosomal abnormalities may not be primary pathogenetic events. The full expression of clonal disorders may require several pathogenetic events, which may occur in variable order.
Baer
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Dessypris
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D000753:Anemia, Refractory / Q000139:chemically induced / Q000150:complications / Q000235:genetics*; D001853:Bone Marrow / Q000648:ultrastructure; D002617:Chemical Industry; D002872:Chromosome Deletion; D002905:Chromosomes, Human, 4-5 / Q000648:ultrastructure*; D002999:Clone Cells / Q000473:pathology; D006410:Hematopoiesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000473:pathology; D013921:Thrombocytopenia / Q000209:etiology