Glycine encephalopathy

Gene : GLDC

What is glycine encephalopathy?

Glycine encephalopathy (GCE) is an inherited disorder caused by the build-up of glycine, a building block of proteins, in tissues and organs of the body, especially the brain. This is caused by a defective complex of enzymes that work together to break down glycine. GCE is also known as nonketotic hyperglycinemia. Typically symptoms begin to appear within the first few days of life. These symptoms include feeding difficulties, weak muscle tone, progressive lack of energy, and abnormal jerking movements and breathing problems. Death often occurs soon after in the most severe cases. For those children affected with GCE who survive infancy, they often develop intellectual disability and seizures as they get older, in addition to the previous symptoms. In some rare cases children may have milder symptoms that start to appear later on in infancy, or symptoms may not appear until adulthood. There is no cure for GCE, but medical care and surveillance may help to improve some symptoms and overall condition of life. One of the causes of GCE is pathogenic mutations in the GLDC gene.

How is glycine encephalopathy inherited?

GCE is inherited in an autosomal recessive manner. This type of inheritance requires the presence of two copies of a pathogenic variant for a person to have the genetic disease. Both parents must be carriers of a pathogenic variant in the gene in order to be at risk to have an affected child. The child must inherit a pathogenic variant from each carrier parent in order to be affected. There is a 1 in 4 chance that a baby will inherit two mutated copies of the gene and be affected when both parents are carriers.

What does it mean to be a carrier?

There are generally no signs or symptoms associated with being a carrier for GCE. However, the risk to have a child affected with GCE is increased. Testing of reproductive partners is recommended for carriers of GCE.

How common is glycine encephalopathy?

It is unknown how common GCE is worldwide, but it appears to be more common in Finland, where it affects 1 in 55,000 newborns, and in British Columbia, Canada, where it affects 1 in 63,000 newborns.

Family References and Resources
Clinician References
What is Analyzed?
  • Full gene sequencing
Affected Systems



Carrier Rates
Detection Rate
Carrier Frequency
General Population 80% 1 in 135

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