Glycogenosis type 6

Overview

A rare, generally mild form of inherited glycogen storage disease where a deficiency of phosphorylase b kinase leads to hypoglycemia and accumulation of glycogen in the liver.

Symptoms

* Enlarged liver * Ketosis * Low blood sugar * Growth retardation * Faintness * Weakness * Hunger * Nervousness * Increased liver glycogen level

Causes

Almost all glycogen storage diseases (Types I through V and Type VII) are transmitted as autosomal recessive traits. The transmission mode of Type VI is unknown; Type VIII may be an X-linked trait. The most common glycogen storage disease is Type I — von Gierke’s, or hepatorenal glycogen storage disease — which results from a deficiency of the liver enzyme glucose-6-phosphatase. This enzyme converts glucose-6-phosphate into free glucose and is necessary for the release of stored glycogen and glucose into the bloodstream, to relieve hypoglycemia. Infants may die of acidosis before age 2; if they survive past this age, with proper treatment, they may grow normally and live to adulthood, with only minimal hepatomegaly. However, there’s a danger of adenomatous liver nodules, which may be premalignant.

Prognosis

often symptoms are so mild that they're not noticed until adulthood