Liver disease is frequently observed in Down syndrome patients with transient abnormal myelopoiesis.

Transient abnormal myelopoiesis (TAM) in neonates with Down syndrome (DS) is characterized by the transient appearance of blast cells, which resolves spontaneously. Approximately 20 % of patients with TAM die at an early age due to organ failure, including liver disease. We studied 25 DS-TAM patients retrospectively to clarify the correlation between clinical and laboratory characteristics and liver diseases. Early death (<6 months of age) occurred in four of the 25 patients (16.0 %), and two of those four patients died due to liver failure. Although physiologic jaundice improved gradually after a week, all DS patients had elevated D-Bil levels during the clinical course of TAM, except one who suffered early death. The median peak day of the WBC count, total bilirubin (T-Bil) and D-Bil levels was: day 1 (range day 0-57), day 8 (range day 1-55), and day 17 (range 1-53), respectively. Our results reveal that all patients with DS-TAM may develop liver disease irrespective of the absence or presence of symptoms and risk factors for early death. In patients of DS-TAM, careful observation of the level of D-Bil is needed by at least 1 month of age for the detection of liver disease risk.