Nonketotic Hyperglycinemia (NKH)

A Rare Inherited, Incurable Metabolic Disorder

Nonketotic Hyperglycinemia (NKH)

A few months ago, a couple I know had twin girls. Beautiful, perfect babies, healthy and thriving …or so we thought… A few hours after they were born, thing began to happen. They became lethargic and could not be awakened. They ceased to respond. They were locked away in a deep, unresponsive sleep and they never woke up. The family was given the horribly sadnews. Both of their beautiful baby girls had a condition called nonketotic hyperglycinemia and would die. For other's who have not heard of this inherited metabolic disorder, or want to learn more about it, I decided to do some research. I was surprised on how little information there was on this terribly sad disease.

Nonketotic Hyperglycinemia(NKH)

Nonketotic hyperglycinemia (NKH) is listed by the ORD (Office of Rare Diseases) of the National Institutes of Health as a rare and incurable inherited metabolic disorder. That means that nonketotic hyperglycinemia affects less than 200,000 individuals in the United States.

NKH, or glycine encephalopathy (GCE), as it is sometimes called, has a very wide spectrum of severity. Most babies born with this disorder die shortly after birth, Before death, theygo through a period of lethargy, weak cry, generalized hypotonia (limp, floppy) absent reflexes and periodic myoclonic jerks (brief seizures). Sometimes a child survives for a few years, but with various degrees of mental retardation.

NKH is an autosomal recessive genetic trait and is unknowingly passed down from generation to generation. This faulty gene only emerges when two carriers have children together and pass it to their offspring. For each pregnancy of two carriers, there is a 25% chance that the child will be born with the disease and a 50% chance that child will be a carrier for the gene defect.