TRISOMY-21 IN TRANSIENT MYELOPROLIFERATIVE DISORDER

Transient leukemia in phenotypically normal children is rare. A newborn child in whom fever and tachypnea developed at age 2 days had a white blood cell count of 20.1 × 109/L and many abnormal blast cells. Chromosome analysis of spontaneously dividing cells from the blood showed these to have trisomy 21, and 80% of cells in the marrow were also trisomic. No trisomic cells were present in skin fibroblast cultures. At age 6 months, at which time the blood film appeared normal, trisomic cells were no longer present. © 1990.