Atypical Hemolytic-Uremic Syndrome (aHUS) Registry is a study collecting safety data on patients with aHUS. This condition affects the blood and kidneys, causing damage to small blood vessels. Two treatments involved are *eculizumab* and *ravulizumab*. These are medications that help prevent further damage to blood vessels. The study will gather information about patients who are using these treatments and those who are not, to understand how the disease progresses.

Eligibility: Anyone diagnosed with aHUS can participate, including children. You need to be able to give consent or have a guardian give consent for you. Certain blood tests are required to join. You cannot participate if your condition is caused by a specific bacteria called Shiga Toxin-producing E. coli (STEC).

• Participation involves sharing medical information during the study.
• No specific treatment is provided as part of the study.
• It helps researchers learn more about the safety of the treatments and the disease.