What is the most common fatal liver disorder in children?

Biliary atresia is recognized as the most common fatal liver disorder affecting children. This condition is characterized by the progressive destruction of the bile ducts, which can lead to severe liver damage if not diagnosed and treated early. The bile ducts, which are crucial for the proper drainage of bile from the liver to the intestines, become blocked or absent, resulting in bile accumulation within the liver, leading to cholestasis and subsequent liver injury.

Early intervention, often involving surgical procedures such as the Kasai procedure, can help restore bile flow and prevent or delay liver failure. The critical aspect of biliary atresia is that it typically presents in the first few months of life, making prompt diagnosis essential for altering the disease's course. Without treatment, children with biliary atresia have a high risk of developing liver cirrhosis, which can be fatal, underlining its position as the leading liver disorder that results in mortality among pediatric patients.

In contrast, the other conditions mentioned are less common in children or may occur with different prevalence or characteristics.