Novel tandem triplication of 1q in a patient with a myelodysplastic syndrome.

This is a report of a patient with a myelodysplastic syndrome characterized by symptomatic neutropenia whose bone marrow aspirates have consistently demonstrated an unusual cytogenetic anomaly. The abnormality present in all metaphases consisted of a tandem triplication of a portion of the long arm of chromosome #1, resulting in tetrasomy of a section of this chromosome ( 1q21 -32). Duplications of this portion of chromosome #1 were observed as a nonrandom event in various malignant states. In addition, these precise breakpoints can be increasingly correlated with tandem duplications.