An 8-year-old boy presented with recurrent skin ecchymoses for the last few months. On examination; he has café-au-lait spots, microcephaly and absent thumb. Of the following, the MOST likely diagnosis is

An 8-year-old boy presented with recurrent skin ecchymoses for the last few months. On examination; he has café-au-lait spots, microcephaly and absent thumb. Of the following, the MOST likely diagnosis is

The best diagnostic study for iron deficiency in an otherwise healthy child is

A common significant feature of blood smear in lead poisoning is

Which of the following viruses can cause aplastic crises in chronic hemolytic disease?

All the following cause autoimmune hemolytic anemia through mechanical damage of the RBCs EXCEPT