What is non Ketotic hyperglycinemia?

Nonketotic hyperglycinemia is a disorder characterized by abnormally high levels of a molecule called glycine in the body (hyperglycinemia). The excess glycine builds up in tissues and organs, particularly the brain. Affected individuals have serious neurological problems.

How is Nonketotic hyperglycinemia diagnosed?

Molecular analysis is an excellent confirmatory test. With sequencing and deletion/duplication analysis, 98% of alleles are detected. Brain MRI imaging can also be helpful because there is a specific pattern of changes seen in individuals with NKH. Prenatal diagnosis is available when familial mutations are known.

What are symptoms of hyperglycinemia?

Signs of nonketotic hyperglycinemia (NKH) can begin any time from infancy to adulthood and include:

  • Sleeping longer or more often.
  • Weak muscle tone (also known as hypotonia)
  • Wandering eye movements.
  • Abnormal jerky movements.
  • Difficulty feeding.
  • Difficulty breathing.
  • Developmental delay.

How rare is Nonketotic hyperglycinemia?

NKH belongs to a larger group of medical conditions called “inborn errors of metabolism.” These are genetic defects that lead to problems making certain chemical conversions in the body. NKH is a rare condition: it is diagnosed in roughly one in 60,000 newborns.

How long do kids live NKH?

“Individuals with this have significant neurological impairments, and they are unable to walk or talk, and they generally will continue to have progression of their disease,” Dr. Neena Champaigne at Greenwood Genetic Center said. One in roughly 70,000 babies are born with NKH. The average life expectancy is age 2.

How long do children with NKH live?

Being a fatal disease, NKH has devastating consequences. The majority of patients die within the first week of life and those who survive suffer from severe mental retardation [11].

What causes low glycine levels?

Glycine levels are low in diabetes, hypothyroidism, obesity, and after intense exercise. Clinically, low glycine levels are suspected in depression. Possible generalized tissue loss, glycine being part of the nitrogen pool and important in gluconeogenesis.

How does glycine affect the brain?

As a neurotransmitter, glycine both stimulates and inhibits cells in the brain and central nervous system, affecting cognition, mood, appetite and digestion, immune function, pain perception, and sleep. Glycine is also involved in the production of other biochemicals that influence these body functions.

What is NKH disease life expectancy?

Why does glycine make you sleepy?

Summary Glycine may promote sleep and enhance the quality of your sleep through its calming effects on the brain and its ability to lower core body temperature.

What is non ketotic hyperglycinemia?

General Discussion. Non-ketotic hyperglycinemia (NKH) is a rare, genetic, metabolic disorder caused by a defect in the enzyme system that breaks down the amino acid glycine, resulting in an accumulation of glycine in the body’s tissues and fluids.

What are the signs and symptoms of attenuated nonketotic hyperglycinemia?

The signs and symptoms of the attenuated form of nonketotic hyperglycinemia are similar to, but milder than, those of the severe form of the condition. Children with attenuated nonketotic hyperglycinemia typically reach developmental milestones, although the skills they achieve vary widely.

What are the classic and attenuated forms of neonatal ketoacidosis (NKH)?

The classical form is then further divided into severe disorder or an attenuated form (mild form). The severe classic form of NKH typically presents in the first week of life with low muscle tone, lethargy, seizures, coma, and apnea requiring ventilator support.

What are the symptoms of hyperglycinemia in newborns?

Severe nonketotic hyperglycinemia is more common. Affected babies experience extreme sleepiness (lethargy) that worsens over time and can lead to coma. They can also have weak muscle tone (hypotonia) and life-threatening breathing problems in the first days or weeks of life.