What is GCE?
GCE or Glycine Encephalopathy is a genetic condition wherein there is abnormal metabolism of glycine in the body. This disorder is also called “nonketotic hyperglycinemia” and involves increased accumulation of glycine in tissues of the body, such as the brain.
Glycine is an amino acid and a neurotransmitter responsible for signal transmission to the brain. Normally, glycine is broken down by an enzyme to become protein. When this particular enzyme is not able to break glycine, it will cause an increase in concentration of this substance in the body. And since it is a neurotransmitter, glycine usually builds up in the brain leading to serious neurological problems.
There are various types of GCE and the classic type is apparent immediately after birth. Newborns with GCE usually appear lethargic, have weak muscles, are difficult to feed, have muscle twitching and even breathing problems. These are just the first symptoms that can be seen on a newborn. When a baby survives to grow a little older, he/she is almost certain to have mental problems and may experience seizures all too often. Another type of GCE is the “infantile” type in which symptoms are noticed by around 6 months of age. As with the classic type, these infants will also have sensory and motor problems leading to abnormal limb movements, behavioral difficulties, and also mental disability. There are also GCE’s that appear later in life, some during childhood, while others have symptoms in adulthood.
Diagnosis of GCE usually involves checking of glycine concentration in the blood and CSF or cerebrospinal fluid. Other doctors also may require molecular genetic testing, urine organic acid analysis, and enzyme testing among others. Treatment meanwhile is geared towards management of symptoms, as there is no known cure for GCE. Management may also vary depending on the type of GCE and manifestations of the disorder.