Inherited ADMATS13 deficiency: When to evoke the in the newborn?

Inherited ADMATS13 or Upshaw-Schulman syndrome (USS) is caused by the deficiency of the Von Willebrand factor-cleaving protease. It is characterized by recurrent episodes of thrombocytopenia reversible by fresh frozen plasma (FFP) infusions, microangiopathic hemolytic anemia, and microvascular thrombosis leading to ischemic damage of multiple organs with end stage renal failure, or neurological sequelae in the absence of appropriate treatment. The typically reported features of USS in neonates are severe jaundice with hyperbilirubinemia, thrombocytopenia and /or combs negative hemolytic anemia, and an increased creatinine.We presented a clinical case of USS with unusual features, which delayed the diagnosis.USS was declared at sixth hours of life with diffuse hemorrhage related to an early neonatal infection. Analysis of the plasma, at the age of 20 months, revealed low ADAMTS13 activity in the patient (<1%).Inherited ADMATS13 deficiency manifestations may overlap with other conditions, which may delay diagnosis and lead to visceral and neurological damage. The diagnosis should be, early considered in some clinical conditions: discrepancy between the severity of a hemorrhagic syndrome and thrombocytopenia, recurrence, resistance to symptomatic treatment. The diagnosis can be suggested by the normalization of platelet count after FFP transfusions.