Glycogen storage disease type IX with enlarged livers. Glycogen storage disease type IX Glycogen storage disease type IX is a hereditary deficiency of glycogen phosphorylase kinase B that affects the liver and skeletal muscle tissue. It is inherited in an X-linked or autosomal recessive manner. The signs and symptoms in glycogen storage disease type IX include: Most of these signs and symptoms diminish as adulthood sets in. Glycogen storage disease type IX can be inherited via: The diagnosis of glycogen storage disease IX consists of the following: There are two types of this inherited condition, "glycogen storage disease IXa1" and "glycogen storage disease IXa2" that
Glycogen-branching enzyme deficiency caused by an autosomal recessive mutation to the GBE1 gene, which leads glycogen branching enzyme activity that is reduced to absent. Subsequently, glycogen molecules are produced with few branches, which greatly decreasing the number of nonreducing ends, drastically slowing the rate at which the molecule can be synthesized or broken down. This causes low levels of muscle glycogen that is very resistant to amylase. Lacking proper glycogen storage, the horse's brain, heart muscle, and skeletal muscles cannot function, leading to rapid death. Most foals with glycogen-branching enzyme deficiency (GBED) are aborted (usually in the second trimester), or are stillborn, and