Of the 2 patients in group 1 who carried THBD variants, one had a native diagnosis of HUS and developed recurrent TMA in the allograft, and the other patient carried a variant of THBD (C224G), which is novel and rare, with a very low allele frequency of 6.62 × 10−7 (unlike other published THBD variants). Here, THBD is linked to hemolytic-uremic syndrome.