Inborn error of amino acid synthesis: human glutamine synthetase deficiency.
Glutamine synthetase (GS) is ubiquitously expressed in human tissues, being involved in ammonia detoxification and interorgan nitrogen flux. Inherited systemic deficiency of glutamine based on a defect of glutamine synthetase was recently described in two newborns with an early fatal course of disease. Glutamine was largely absent in their serum, urine and cerebrospinal fluid. Each of the patients had a homozygous mutation in the glutamine synthetase gene and enzymatic investigations confirmed that these mutations lead to a severely reduced glutamine synthetase activity. From the observation in the first patients with congenital glutamine synthetase deficiency, brain malformation can be expected as one of the leading signs. In addition, other organ systems are probably involved as observed in one of the index patients who suffered from severe enteropathy and necrolytic erythema of the skin. Deficiency of GS has to be added to the list of inherited metabolic disorders as a rare example of a defect in the biosynthesis of an amino acid.
Häberle
Johannes
J
Klinik und Poliklinik für Kinder- und Jugendmedizin, Universitätsklinikum Münster, Albert-Schweitzer-Str. 33, 48129, Münster, Germany. haeb@uni-muenster.de
Görg
Boris
B
Toutain
Annick
A
Rutsch
Frank
F
Benoist
Jean-François
JF
Gelot
Antoinette
A
Suc
Annie-Laure
AL
Koch
Hans Georg
HG
Schliess
Freimut
F
Häussinger
Dieter
D
D000592:Amino Acid Metabolism, Inborn Errors / Q000150:complications / Q000235:genetics / Q000378:metabolism*; D001921:Brain / Q000002:abnormalities; D003677:Deficiency Diseases / Q000209:etiology; D017809:Fatal Outcome; D005260:Female; D047109:Fetal Development; D005974:Glutamate-Ammonia Ligase / Q000172:deficiency* / Q000235:genetics / Q000378:metabolism; D005973:Glutamine / Q000378:metabolism*; D006720:Homozygote; D006801:Humans; D007231:Infant, Newborn; D008099:Liver / Q000201:enzymology; D016031:Liver Transplantation / Q000009:adverse effects; D008279:Magnetic Resonance Imaging; D008297:Male; D009102:Multiple Organ Failure / Q000209:etiology; D009154:Mutation; D013262:Stevens-Johnson Syndrome / Q000209:etiology / Q000473:pathology
D005973:Glutamine; D005974:Glutamate-Ammonia Ligase