Which enzyme deficiency is linked to Andersen's disease?

Andersen's disease, also known as glycogen storage disease type IV, is associated with a deficiency of the branching enzyme. This enzyme plays a critical role in glycogen synthesis by adding α(1→6) branches to the glycogen polymer. In the absence of this enzyme, glycogen accumulates in a more linear form, leading to an abnormal structure known as "amylopectin-like" glycogen. This abnormal glycogen is less soluble and more prone to causing damage, particularly in hepatic tissues, which can lead to liver dysfunction, cirrhosis, and eventually liver failure in affected individuals.

The pathophysiology of Andersen's disease highlights the importance of proper glycogen structure for normal metabolism. Due to the lack of branching, affected individuals may exhibit various symptoms including stunted growth, liver enlargement, and muscle weakness. Overall, it is the specific deficiency in the branching enzyme that is pivotal to the disease's manifestation.