Congenital thrombotic thrombocytopenic purpura masquerading as vitamin B12 deficiency

Congenital thrombotic thrombocytopenic purpura (CTTP), also called Upshaw-Schulman syndrome (USS), is a rare autosomal recessive disorder resulting from the deficiency of the ADAMTS13. CTTP is characterized by the formation of platelet-rich thrombi in small vessels of multiple organs, resulting in thrombocytopenia and microangiopathic hemolytic anemia, eventually leading to organ failure.

We present a case of an 11-month-old male infant with CTTP lacking classic features of the disease. Instead, his clinical picture portrayed vitamin B12 deficiency, leading to misdiagnosis and subsequent treatment delay.

This case led to the conclusion that congenital TTP should be suspected in case of vitamin B12 deficiency if the child does not respond to the vitamin B12 replacement therapy. We also emphasize that management for CTTP should be started at its earliest in case of increased clinical suspicion to avoid worse outcomes, especially in countries lacking rapid availability of enzyme assay.