# Unusual Presentation of Aggressive Atypical Hemolytic Uremic Syndrome With Brugada Syndrome

## TL;DR

A 15-year-old girl with atypical hemolytic uremic syndrome and Brugada syndrome showed initial improvement with treatment but ultimately died after complications.

## Contribution

This paper presents a rare case of atypical HUS co-occurring with Brugada syndrome and highlights treatment challenges.

## Key findings

- The patient had a CFH gene variant and atypical HUS confirmed by genetic testing.
- Eculizumab treatment led to initial improvement, but non-compliance caused deterioration.
- The patient died after complications including kidney damage and multiple treatment attempts.

## Abstract

Hemolytic uremic syndrome (HUS) is part of a spectrum of disorders known as thrombotic microangiopathies. These disorders are characterized by giving rise to platelet microthrombi, which subsequently develop hemolytic anemia and thrombocytopenia. In HUS, the kidneys are destroyed, mainly due to damage to the renal blood vessels. HUS can be typical or atypical, depending on the cause, and can lead to significant mortality rates. We herein report an unusual case of atypical HUS in a 15-year-old female who presented with fatigue, abdominal pain with nausea and vomiting, loss of appetite, and urine discoloration. Further tests showed low platelets with significant anemia. She was diagnosed with atypical HUS after discovering that she had no previous bloody diarrhea episode with a negative E. coli strain, O157:H7, alongside valid ADAMTS13 activity. The diagnosis was confirmed by genetic testing, and a variant of uncertain significance was found in the CFH gene. The patient, therefore, was started on eculizumab, and a follow-up was done once or twice a month through blood testing. She showed significant improvement. Due to non-compliance with the eculizumab treatment, the patient showed deterioration numerous times. A kidney biopsy was subsequently done, showing signs of acute to chronic thrombotic microangiopathy with moderate tubular atrophy and interstitial fibrosis. After many hemodialysis and plasma exchange sessions and being put on several treatments, such as prednisolone and rituximab, the patient faced death after one year.