eng Science and Education Publishing American Journal of Medical Case Reports 2374-216X 2022-05-05 10 5 117 121 10.12691/ajmcr-10-5-1 AJMCR20221051 article Sabina Kumar 1 Chukwuemeka Umeh 1 Prithi Choday 1 John Carvalho 1 Sobiga Ranchithan 2 Sumanta Chaudhuri 2 Pranav Barve Barve.MD@sevenstar.health 2 Department of Internal Medicine, Hemet Global Medical Center, Hemet, California, USA American University of Antigua Thrombotic microangiopathies (TMAs) are clinical conditions classified by a combination of low platelets causing microthrombi, which can ultimately lead to hemolytic anemia. The most common conditions include thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome (HUS). In this case report, we focused on a rare subtype of HUS. A 25-year old female presented to our tertiary care facility from a community hospital with nausea, vomiting, and bloody diarrhea after consuming mussels. A presumptive diagnosis of TTP was given and unfortunately treatment efforts did not improve the patient¡¯s status. Investigative laboratory studies showed leukocytosis, thrombocytopenia, presence of schistocytes on peripheral smear, and no evidence of hemoglobinuria. The patient had negative Shiga toxin and E.coli 0157 and imaging showed diffuse colitis. Despite antibiotics, dialysis and plasmapheresis efforts, the patient¡¯s condition worsened and she developed severe sepsis and was then intubated. At that point, an atypical HUS genetic test result demonstrated a heterozygous missense variant, and she was emergently started on eculizumab and steroids which improved her condition. This case illustrates an atypical presentation for thrombotic microangiopathy, complicated by significant multiorgan dysfunction. http://pubs.sciepub.com/ajmcr/10/5/1/ajmcr-10-5-1.pdf Thrombotic microangiopathy thrombotic thrombocytopenic purpura (TTP) atypical hemolytic uremic syndrome (aHUS) thrombocytopenia anemia microthrombi Escherichia coli 0157:H7 complement Eculizumab plasmapheresis pregnancy