#00063302

A 22-day-old male child was diagnosed to Down syndrome and referred to a tertiary care center with a high total white blood cells count. Physical examination showed mongoloid slant in his eyes and sandal gap in his toes. The baby had a phenotype consistent with Down syndrome.

Laboratory evaluation showed high blood counts. Day 22 blood investigation showed Hb 13.5 g/dl, TLC:30200/cu.mm, and platelet count 8,72,000/cu.mm. Peripheral smear showed 18% blasts exhibiting high N:C ratio, fine chromatin, visible nucleoi and scant cytoplasm. Thrombocytosis noted with large and anisogranular platelets. Transient myeloproliferative disorder associated with Down syndrome was suspected. 

Immunophenotyping by flowcytometry showed 19% gated population with  bright expression for myeloid antigen (CD33 and CD117).