Recurrent pancreatitis and atypical hemolytic uremic syndrome (aHUS): an unusual presentation in childhood.

Hemolytic uremic syndrome (HUS) is a thrombotic microangiopathy characterized by the classical triad of acute hemolytic anemia, thrombocytopenia, and kidney impairment. We report a 10-year-old boy with acute pancreatitis presenting simultaneously with atypical HUS (aHUS) with two such episodes occurring 1 year apart. The child presented with abdominal pain, vomiting, oliguria, epigastric tenderness, and had a right undescended testis. During the initial episode, anti-factor H antibodies were mildly elevated while they were normal in the subsequent episode with normal complement components. Whole exome sequencing identified a heterozygous pathogenic CFTR variant, predisposing to recurrent pancreatitis and cryptorchidism, as well as a probable heterozygous CFHR1/CFHR3 deletion, the gene responsible for recurrent aHUS. Treatment of pancreatitis, hemodialysis, and plasma infusions led to complete recovery of acute kidney injury (AKI) and HUS on both occasions.