Glycogen Storage Disease, Type 0 (GYS2)

Glycogen storage disease, type 0 is an autosomal recessive disease caused by pathogenic variants in the gene GYS2. The onset for this disorder occurs in infancy or early childhood, and symptoms include drowsiness, sweating, lack of attention, fasting hypoglycemia associated with hyperketonemia, seizures, and a low-normal reference range of lactate and alanine levels in blood. Long-term complications of this disorder may include growth delay, osteopenia, developmental delay, intellectual deficits, and personality changes. Since affected individuals develop fasting hypoglycemia within a few hours after eating due to the limited storage of hepatic glycogen and inadequate gluconeogenesis, treatment involves attempting to maintain normoglycemia. The life expectancy for this disorder is normal.

For information about carrier frequency and residual risk, please see the residual risk table.

This gene is included on the following panel(s):