Non-keto high glycine hyperlipidemia diagnosis and treatment

National Taiwan University Hospital from 1996 to 2003 who diagnose and treat or assist in the treatment of six suffer from this disease of the newborn. They began manifestations include lethargy and apnea, age of onset is about 1-3 days old, all of the patients, especially newborns hiccup Individually phenomenon, and can be observed soon after birth. These patients will gradually show local or systemic cramps or muscle clonus, antiepileptic drugs ineffective control of these movements, usually need several drugs used simultaneously in order to mitigate the situation myoclonus. All patients are in compliance with the diagnosis of non-ketone high glycine hyperlipidemia, including cerebrospinal fluid glycine values ​​have increased, blood values ​​have increased glycine and glycine value of cerebrospinal fluid to blood ratio of glycine value greater than 0.08. Individually these patients special brainwave changes, in line with non-ketone high glycine hyperlipidemia diagnosis.
These patients are at about the full moon began to accept for non-keto high glycine hyperlipidemia rare drug treatment, including Sodium benzoate and Dextromethorphan. Sodium benzoate in order to reduce the concentration of glycine special drugs, but in these patients, the use of Sodium benzoate, although blood glycine value can be restored to normal, but cerebrospinal fluid glycine values ​​rarely fall to the normal range inside.
Dextromethorphan (common trade name Medicon) is generally used to cough, but in these patients, the use of high doses of Dextromethorphan (20-35 mg per kg of body weight) can reduce muscle tension and slow cramp cramps phenomenon. In addition, these patients in the neonatal period, the phenomenon has intractable spasticity, may need to use several kinds of anti-epileptic drugs. In the aftermath of context, these patients had severe head, ankylosing quadriplegia, and severe developmental delay phenomenon. Including three patients because of aspiration pneumonia or related complications died of a half, three, and five years old. A patient's brother, also in three days of age began to show symptoms, after adequate genetic counseling, the parents decided to forgo aggressive treatment, so we do not have kids for intubation and respirator use, just give oxygen therapy. The patient died in five days is large. As for the rest of the two patients, the current three and a half and two years, respectively, are brain MRI showed severe brain atrophy and white matter lesions, neurological development is less than four months old baby.
Currently the newborn Nonketotic high glycine hyperlipidemia treatment, although there Sodium benzoate and Dextromethorphan cure, but the treatment is still to be unsatisfactory outcome. Even if early treatment can not save the damaged brain cells. As for the remaining nerve cells because high concentrations of glycine by sustained stimulation caused intractable spasticity. So now this kind of patient, the prognosis is quite optimistic.
As for the prenatal diagnosis, currently abroad for someone using chorionic cells enzyme test, but there are still false positive and false negative issues need to be overcome. If the house had children and have found genetic mutations, can make use of genetic testing, do prenatal diagnosis. But for the point mutation did not find a family, we can only rely on the enzyme test to diagnose. Based on these difficulties, we give the parents of these six patients adequate genetic counseling, they must face their own future reproductive choices.

Nonketotic hyperglycinemia, NKH

Disease genes
GLDC gene, AMT gene
Sheng line rate
1/12, 000 (Finland); Taiwan no statistical data
Clinical symptoms

    Non-keto high glycine hyperlipidemia type can be divided into the newborn (neonatal type) and late-onset (late-onset type) categories.Neonatal type is more common in neurological symptoms within a few days after birth and rapid deterioration occurs, there will be low muscle tone, low Moro test reaction, epilepsy, suffocation, drowsiness or coma. Most of the patients will die within a few weeks, and after a period of time, there are still survivors of severe psychomotor developmental delay phenomenon. In addition, there may be various types of seizures cramps, ascending from myoclonic epilepsy epileptic seizures and so may occur, as well as the situation is also very common hiccup. Neonatal period there is no obvious low muscle tone, muscle stiffness will then gradually become.Late-onset cases in the neonatal period there will be no abnormal symptoms, then it will slowly develop various degrees of neurological symptoms, age of onset ranging from infancy to adolescence. [The above information is extracted from the rare disease Foundation]
    Nonketotic hyperglycinemia (NKH) is an autosomal recessive genetic disease that causes the glycine cleavage enzyme complex (glycine cleavage enzyme complex, referred GCS) abnormality, the enzyme from the P, T, H, L four proteins, the present study shows that nearly 80% NKH patients is due to the P protein abnormalities, while nearly 10-15% of patients with T protein abnormalities. P protein is glycine decarboxylase (GLDC) gene product; and T protein aminomethyltransferase (AMT) gene product.
Genetic model
Autosomal recessive

Test methods
GLDC gene, AMT gene sequence analysis
Specimen requirements
Adults: 3 ml of whole blood Prenatal: fluff (10mg or more), amniotic fluid (10ml) or umbilical cord blood (2ml)
Reporting schedule
2 weeks
Inspection Limitations
1 The molecular genetic testing to direct gene sequencing method to detect because patients or those with AMT in GLDC genes and gene exon (exon) region causative mutation has occurred, if the detection of large deletions or sequence of the region mutations can not be learned by the test.(2) If the cause of the disease in patients with non-gene cause, they can not detected by the test.3 reported accuracy was 97%, the results for physician clinical reference.